Update actions/cache action to v4

| datasource  | package       | from   | to     |
| ----------- | ------------- | ------ | ------ |
| github-tags | actions/cache | v3.3.3 | v4.0.0 |

Author: renovate[bot]

.github/workflows/tests.yml

@@ -15,7 +15,7 @@ jobs:
         uses: docker/[email protected]
 
       - name: Cache Docker layers
-        uses: actions/cache@v3.3.3
+        uses: actions/cache@v4.0.0
         with:
           path: /tmp/.buildx-cache
           key: ${{ runner.os }}-buildx-${{ github.sha }}