force cache update also on hit

Author: kinkie

.github/workflows/gen-docs.yaml

@@ -38,7 +38,8 @@ jobs:
         uses: actions/cache@v4
         with:
           path: last-squid-commit.txt
-          key: squid-last-commit-hash
+          key: last-commit-hash-${{ github.run_id }}
+          restore-keys: last-commit-hash
 
       - name: Check for squid source updates
         id: check_squid_updates