Use actions/cache v4 DEVOPS-2662

Author: dcrossleyau

.github/workflows/docker.yml

@@ -33,7 +33,7 @@ jobs:
           images: ghcr.io/${{ github.repository }}
 
       - name: Cache Docker layers
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: /tmp/.buildx-cache
           key: ${{ runner.os }}-buildx-Dockerfile }}