Revert "ci: add multi-platform Docker image support for ARM64 (#1180)"

This reverts commit ddc57f21f9.

.github/workflows/docker.yml

@@ -52,10 +52,6 @@ jobs:
           echo "PUMPKIN_VERSION=$(echo $VERSION | cut -d '+' -f 1)" >> $GITHUB_ENV
           echo "MC_VERSION=$(echo $VERSION | cut -d '+' -f 2)" >> $GITHUB_ENV
 
-      - name: Set up QEMU
-        if: steps.repo_check.outputs.should_deploy == 'true'
-        uses: docker/setup-qemu-action@v3
-
       - name: Extract Metadata
         if: steps.repo_check.outputs.should_deploy == 'true'
         id: meta
@@ -78,16 +74,7 @@ jobs:
         if: steps.repo_check.outputs.should_deploy == 'true'
         uses: docker/build-push-action@v6
         with:
-          platforms: linux/amd64,linux/arm64
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           annotations: ${{ steps.meta.outputs.annotations }}
-
-      - name: Generate SBOM
-        if: steps.repo_check.outputs.should_deploy == 'true'
-        uses: anchore/sbom-action@v0
-        with:
-          image: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
-          format: spdx-json
-          artifact-name: sbom-pumpkin-${{ env.PUMPKIN_VERSION }}