Use ubuntu-26.04 runners in all GitHub workflows

Install clang-19 from the Ubuntu archive, as apt.llvm.org has no LLVM 19 repository for 26.04.

.github/workflows/AppFwkUnitTest.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, windows-2025-vs2026]
+        os: [ubuntu-26.04, windows-2025-vs2026]
         qtver: [6.6.3]
         include:
           - qtver: 6.6.3

.github/workflows/ResInsightWithCache.yml

@@ -37,8 +37,8 @@ jobs:
               ri-unit-test-path: "ApplicationLibCode/UnitTests/ResInsight-tests",
             }
           - {
-              name: "Ubuntu 24.04 gcc",
-              os: ubuntu-24.04,
+              name: "Ubuntu 26.04 gcc",
+              os: ubuntu-26.04,
               cc: "gcc-14",
               cxx: "g++-14",
               build-python-module: true,
@@ -53,8 +53,8 @@ jobs:
               ri-unit-test-path: "ApplicationLibCode/UnitTests/ResInsight-tests",
             }
           - {
-              name: "Ubuntu 24.04 clang-19",
-              os: ubuntu-24.04,
+              name: "Ubuntu 26.04 clang-19",
+              os: ubuntu-26.04,
               cc: "clang-19",
               cxx: "clang++-19",
               build-python-module: true,
@@ -165,11 +165,6 @@ jobs:
         run: |
           set -e
           
-          # Add LLVM repository
-          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-          echo "deb http://apt.llvm.org/noble/ llvm-toolchain-noble-19 main" | sudo tee /etc/apt/sources.list.d/llvm-19.list
-          echo "deb-src http://apt.llvm.org/noble/ llvm-toolchain-noble-19 main" | sudo tee -a /etc/apt/sources.list.d/llvm-19.list
-          
           # Update package list and install clang-19
           sudo apt-get update --option="APT::Acquire::Retries=3"
           sudo apt-get install --option="APT::Acquire::Retries=3" -y \
@@ -373,7 +368,7 @@ jobs:
   pypi-publish:
     name: Upload release to PyPI
     needs: build
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     environment:
       name: pypi
       url: https://pypi.org/p/rips

.github/workflows/build-rhel8-image.yml

@@ -30,7 +30,7 @@ concurrency:
 
 jobs:
   build-image:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     # Cold first build runs the full ResInsight compile in the build-warmup
     # stage (~1.5-2 h). Incremental nightly rebuilds reuse the BuildKit cache
     # mount and finish much faster.

.github/workflows/bump-dev-version.yml

@@ -5,7 +5,7 @@ on:
 
 jobs:
   bump-version:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
 
     steps:
       - name: Checkout repository

.github/workflows/check-broken-links.yml

@@ -12,7 +12,7 @@ on:
 
 jobs:
   broken_link_checker_job:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     name: Check for broken links
     steps:
     - name: Check for broken links

.github/workflows/clang-format.yml

@@ -4,7 +4,7 @@ on: [push]
 
 jobs:
   clang-format-job:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Set apt mirror
         # GitHub Actions apt proxy is super unstable

.github/workflows/clang-tidy.yml

@@ -17,7 +17,7 @@ env:
 
 jobs:
   ResInsight-clang-tidy:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Checkout
         uses: actions/checkout@v7

.github/workflows/clazy-report.yml

@@ -11,7 +11,7 @@ env:
 
 jobs:
   ResInsight-clazy:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Checkout
         uses: actions/checkout@v7

.github/workflows/cleanup-rhel8-image.yml

@@ -37,7 +37,7 @@ concurrency:
 
 jobs:
   cleanup:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     permissions:
       packages: write
     steps:

.github/workflows/close-label.yml

@@ -7,7 +7,7 @@ jobs:
   label_issues:
     # Skip issues closed as "not planned" or "duplicate"
     if: github.event.issue.state_reason == 'completed'
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     permissions:
       issues: write
     steps:

.github/workflows/cmake-format.yml

@@ -4,7 +4,7 @@ on: [push]
 
 jobs:
   cmake-format-job:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Install cmakelang for cmake-format
         run: |

.github/workflows/python-linting.yml

@@ -4,7 +4,7 @@ on: [push, pull_request]
 
 jobs:
   lint:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - uses: actions/checkout@v7
       - uses: actions/setup-python@v7

.github/workflows/release-draft.yml

@@ -12,7 +12,7 @@ permissions:
 jobs:
   draft-release:
     name: Create draft release with binaries
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     env:
       GH_TOKEN: ${{ github.token }}
       GH_REPO: ${{ github.repository }}
@@ -75,7 +75,7 @@ jobs:
           cd artifacts
           for d in ResInsight-*/; do
             name="${d%/}"
-            # Spaces in artifact names (e.g. "ResInsight-Ubuntu 24.04 gcc")
+            # Spaces in artifact names (e.g. "ResInsight-Ubuntu 26.04 gcc")
             # make awkward asset filenames, so collapse them to underscores.
             safe="${name// /_}"
             zip -r "../release-assets/${safe}-${{ github.ref_name }}.zip" "$name"

.github/workflows/remove-pending-release.yml

@@ -3,7 +3,7 @@ on:
   workflow_dispatch:
 jobs:
   remove_label:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     permissions:
       issues: write
     steps:

.github/workflows/rhel8-package.yml

@@ -14,7 +14,7 @@ jobs:
   # Resolves the prebuilt CI image name so it works in forks and upstream alike
   # (GHCR requires a lowercase repository path).
   resolve-image:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     outputs:
       image: ${{ steps.meta.outputs.image }}
     steps:
@@ -24,7 +24,7 @@ jobs:
 
   rhel8-package:
     needs: resolve-image
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
       packages: read

.github/workflows/rhel8-unit-tests.yml

@@ -16,7 +16,7 @@ jobs:
   # Resolves the prebuilt CI image name so it works in forks and upstream alike
   # (GHCR requires a lowercase repository path).
   resolve-image:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     outputs:
       image: ${{ steps.meta.outputs.image }}
     steps:
@@ -26,7 +26,7 @@ jobs:
 
   rhel8-build-and-test:
     needs: resolve-image
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
       packages: read

.github/workflows/spell-check-pr.yml

@@ -13,7 +13,7 @@ permissions:
 
 jobs:
   spell-check:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - uses: actions/checkout@v7
         with:

.github/workflows/spell-check.yml

@@ -11,7 +11,7 @@ permissions:
 
 jobs:
   build:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - uses: actions/checkout@v7
       

.github/workflows/test-latest-rips-with-latest-resinsight.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   test-latest-rips:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       actions: read
       contents: read
@@ -50,9 +50,9 @@ jobs:
               per_page: 100,
             });
 
-            const artifact = artifacts.find((candidate) => candidate.name === "ResInsight-Ubuntu 24.04 gcc");
+            const artifact = artifacts.find((candidate) => candidate.name === "ResInsight-Ubuntu 26.04 gcc");
             if (!artifact) {
-              core.setFailed("Could not find artifact 'ResInsight-Ubuntu 24.04 gcc' on selected run");
+              core.setFailed("Could not find artifact 'ResInsight-Ubuntu 26.04 gcc' on selected run");
               return;
             }
 

.github/workflows/update-submodules.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   update-submodules:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     strategy:
       matrix:
         submodule: