Renovate: Update docker/setup-buildx-action action to v4

Author: renovate[bot]

.github/workflows/container-registry-ghcr.yaml

@@ -47,7 +47,7 @@ jobs:
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
       - name: Build and push Docker image
         uses: docker/build-push-action@v6
         with: