Update docker/setup-buildx-action action to v3 (#7)

.github/workflows/docker.yml

@@ -20,7 +20,7 @@ jobs:
         uses: docker/setup-qemu-action@v3
       -
         name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v2
+        uses: docker/setup-buildx-action@v3
       -
         name: Login to DockerHub
         uses: docker/login-action@v3