correct dockerfile name

Author: Jeremy Price

.github/workflows/docker.yml

@@ -143,7 +143,7 @@ jobs:
         uses: docker/build-push-action@v6
         with:
           context: .
-          file: ./Dockerfile-alpine
+          file: ./Dockerfile.alpine
           platforms: linux/amd64
           # For pull requests, we run the Docker build (to ensure no PR changes break the build),
           # but we ONLY do an image push to DockerHub if it's NOT a PR