FEAT: add workflow for cleaning cache after a PR

.github/workflows/clean-cache.yml

@@ -0,0 +1,26 @@
+name: Clean cache
+on:
+  pull_request:
+    types:
+      - closed
+  workflow_dispatch:
+
+jobs:
+  cleanup:
+    env:
+      REPO: ${{ github.repository }}
+      BRANCH: ${{ github.ref }}
+      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    name: Remove PR caches
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - run: gh extension install actions/gh-actions-cache
+      - name: Delete caches of latest PR
+        run: |
+          set +e
+          echo "Deleting caches..."
+          for CACHE_KEY in $(gh actions-cache list -R $REPO -B $BRANCH | cut -f 1); do
+            gh actions-cache delete $CACHE_KEY -R $REPO -B $BRANCH --confirm
+          done
+          echo "Done"

src/repoma/.github/workflows/clean-cache.yml

@@ -0,0 +1 @@
+../../../../.github/workflows/clean-cache.yml

src/repoma/check_dev_files/github_workflows.py

@@ -40,6 +40,7 @@ def update() -> None:
     executor(remove_workflow, "ci-style.yml")
     executor(remove_workflow, "ci-tests.yml")
     executor(remove_workflow, "linkcheck.yml")
+    executor(_copy_workflow_file, "clean-cache.yml")
     if executor.error_messages:
         raise PrecommitError(executor.merge_messages())