Revert "add sourcery.ai github action"

This reverts commit e3f991948a.

Sourcery works right now without adding an action as a webhook, so we
don't need an action that cannot access secrets when triggered from a
pull request.

Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>

.github/workflows/sourcery-check.yml

@@ -1,20 +0,0 @@
-name: Check PR using Sourcery
-
-on: pull_request
-
-jobs:
-  review-with-sourcery:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 0
-
-      - uses: actions/setup-python@v4
-        with:
-          python-version: '3.13'
-
-      - uses: sourcery-ai/action@438ce67e9f15fbeacb72257da23e2fffb1b6d354
-        with:
-          token: ${{ secrets.SOURCERY_TOKEN }}
-          diff_ref: ${{ github.event.pull_request.base.sha }}