other: Build and test localnet on macos

.github/workflows/docker-localnet.yml

@@ -13,7 +13,8 @@ jobs:
     strategy:
       matrix:
         docker_image: [emerald-localnet, sapphire-localnet]
-    runs-on: ubuntu-latest
+        os: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -45,15 +46,22 @@ jobs:
           file: docker/${{ matrix.docker_image }}/Dockerfile
           tags: |
             ghcr.io/oasisprotocol/${{ matrix.docker_image }}:local
+          outputs: type=docker,dest=/tmp/${{ matrix.docker_image }}.tar
           load: true
 
       - name: Test
         timeout-minutes: 3
         working-directory: docker/${{ matrix.docker_image }}
         run: ./test.sh
 
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ matrix.docker_image }}
+          file: /tmp/${{ matrix.docker_image }}.tar
+
       - name: Push
-        if: ${{ github.event_name == 'push' }}
+        if: ${{ github.event_name == 'push' && matrix.os == 'ubuntu-latest' }}
         uses: docker/build-push-action@v6
         with:
           build-args: |
@@ -69,7 +77,7 @@ jobs:
             org.opencontainers.image.revision=${{ github.sha }}
 
       - name: Prune old ghcr.io/oasisprotocol/${{ matrix.docker_image }} images
-        if: ${{ github.event_name == 'push' }}
+        if: ${{ github.event_name == 'push' && matrix.os == 'ubuntu-latest' }}
         uses: vlaurin/action-ghcr-prune@v0.6.0
         with:
           token: ${{ secrets.GITHUB_TOKEN }}