CI: allow overwriting the build cache

Author: cometkim

.github/workflows/ci.yml

@@ -271,6 +271,16 @@ jobs:
         if: runner.os == 'Linux'
         run: opam exec -- dune build --display quiet --profile static
 
+      - name: Delete stable compiler build state
+        if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+        run: |
+          gh actions-cache delete ${{ steps.compiler-build-state-key.outputs.value }} \
+            -R ${{ github.repository }} \
+            -B ${{ github.ref }} \
+            --confirm || echo "not exist"
+        env:
+          GH_TOKEN: ${{ github.token }}
+
       - name: Save compiler build state
         if: github.event_name == 'push' && github.ref == 'refs/heads/master'
         uses: actions/cache/save@v4