change image build to use docker architecture emulation

Until docker/actions-toolkit#317 is fixed use docker emulation to get
arm support.

.github/workflows/docker-image.yml

@@ -9,15 +9,17 @@ on:
 
 jobs:
   build:
+    runs-on: ubuntu-latest
     strategy:
       matrix:
-        # os: [ubuntu-latest]
-        os: [ubuntu-latest, macos-14]
-    runs-on: ${{matrix.os}}
-
+        platform: [linux/amd64, linux/arm64]
+
     steps:
     - name: checkout
       uses: actions/checkout@v4
+
+    - name: Docker QEMU
+      uses: docker/setup-qemu-action@v3
 
     - name: Docker Setup Buildx
       uses: docker/[email protected]
@@ -33,6 +35,7 @@ jobs:
     - name: Build and push
       uses: docker/build-push-action@v6
       with:
+        platform: ${{ matrix.platform }}
         context: "{{defaultContext}}:docker/baseos/gcc1120"
         push: true
-        tags: ngeetropics/baseos:testbuild-${{runner.arch}}
+        tags: ngeetropics/baseos:testbuild-${{ matrix.platform}}