ci(lint): separate lintc from lint

All steps in lint now do now require a Neovim build.

.github/workflows/ci.yml

@@ -18,11 +18,6 @@ concurrency:
 
 jobs:
   lint:
-    # This job tests two things: it lints the code but also builds neovim using
-    # system dependencies instead of bundled dependencies. This is to make sure
-    # we are able to build neovim without pigeonholing ourselves into specifics
-    # of the bundled dependencies.
-
     if: (github.event_name == 'pull_request' && github.base_ref == 'master') || (github.event_name == 'push' && github.ref == 'refs/heads/master')
     runs-on: ubuntu-20.04
     timeout-minutes: 10
@@ -65,7 +60,6 @@ jobs:
             ninja-build \
             pkg-config
 
-
       - name: Cache uncrustify
         id: cache-uncrustify
         uses: actions/cache@v3
@@ -138,6 +132,66 @@ jobs:
         run: |
           git diff --color --exit-code
 
+      - name: Cache dependencies
+        run: ./ci/before_cache.sh
+
+  lintc:
+    # This job tests two things: it lints the code but also builds neovim using
+    # system dependencies instead of bundled dependencies. This is to make sure
+    # we are able to build neovim without pigeonholing ourselves into specifics
+    # of the bundled dependencies.
+
+    if: (github.event_name == 'pull_request' && github.base_ref == 'master') || (github.event_name == 'push' && github.ref == 'refs/heads/master')
+    runs-on: ubuntu-20.04
+    timeout-minutes: 10
+    env:
+      CC: gcc
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Setup common environment variables
+        run: ./.github/workflows/env.sh lint
+
+      - name: Install apt packages
+        run: |
+          sudo add-apt-repository ppa:neovim-ppa/stable
+          sudo apt-get update
+          sudo apt-get install -y \
+            autoconf \
+            automake \
+            build-essential \
+            cmake \
+            gettext \
+            libluajit-5.1-dev \
+            libmsgpack-dev \
+            libtermkey-dev \
+            libtool-bin \
+            libtree-sitter-dev \
+            libunibilium-dev \
+            libuv1-dev \
+            libvterm-dev \
+            locales \
+            lua-busted \
+            lua-check \
+            lua-filesystem \
+            lua-inspect \
+            lua-lpeg \
+            lua-luv-dev \
+            lua-nvim \
+            luajit \
+            ninja-build \
+            pkg-config
+
+      - name: Cache artifacts
+        uses: actions/cache@v3
+        with:
+          path: |
+            ${{ env.CACHE_NVIM_DEPS_DIR }}
+          key: lint-${{ hashFiles('cmake/*', '**/CMakeLists.txt', '!cmake.deps/**CMakeLists.txt') }}-${{ github.base_ref }}
+
+      - name: Build third-party deps
+        run: ./ci/before_script.sh
+
       - name: Build nvim
         run: ./ci/run_tests.sh build_nvim