Revert "build: add docker arm image"

This reverts commit 2d5a8e85f34b3cd373b0644025bd90ce982cfb3b.

.github/workflows/docker.yml

@@ -10,8 +10,6 @@ jobs:
     docker:
         runs-on: ubuntu-latest
         steps:
-            - name: Set up QEMU
-              uses: docker/setup-qemu-action@v2
             - name: Set up Docker Buildx
               uses: docker/setup-buildx-action@v2
             - name: Login to Docker Hub
@@ -27,5 +25,4 @@ jobs:
               uses: docker/build-push-action@v3
               with:
                   push: true
-                  platforms: linux/amd64,linux/arm64
                   tags: peerjs/peerjs-server-test:nightly