Update docker/setup-buildx-action action to v4 (#9)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/docker.yaml

@@ -20,7 +20,7 @@ jobs:
         uses: actions/checkout@v6
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
 
       - uses: docker/login-action@v4
         with: