chore(docker): disable building arm64 docker images temporarily

This reverts commit 8475e1f.
Reference: LukeMathWalker/cargo-chef#107 (comment)

.github/workflows/docker.yml

@@ -35,11 +35,6 @@ jobs:
             type=raw,value=latest
             type=semver,pattern={{version}}
 
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v1
-        with:
-          platforms: arm64
-
       - name: Set up Docker Buildx
         id: buildx
         uses: docker/setup-buildx-action@v1
@@ -73,7 +68,6 @@ jobs:
         with:
           context: ./
           file: ./Dockerfile
-          platforms: linux/amd64,linux/arm64
           builder: ${{ steps.buildx.outputs.name }}
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.meta.outputs.tags }}