ci: only update docker cache if empty or during nighlty builds

Signed-off-by: Salvatore Mesoraca <[email protected]>

.github/workflows/integration.yaml

@@ -57,11 +57,13 @@ jobs:
      steps:
        - uses: actions/checkout@v4
        - name: Cache docker images
+         id: custom-cache
          uses: actions/cache@v3
          with:
            path: ./custom-cache/
            key: custom-cache
-       - name: Update Cache
+       - if: ${{ steps.custom-cache.cache-hit != 'true' || github.event_name == 'schedule' }}
+         name: Update Cache
          run: |
            mkdir ./custom-cache/
            docker compose --profile all build