Add code-mirror workflow

.github/workflows/code-mirror.yml

@@ -0,0 +1,29 @@
+name: Code Mirror
+
+on: [push]
+
+permissions:
+      id-token: write # Permission to fetch OIDC token
+      contents: read
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      # Checkout the repo
+      - uses: actions/checkout@main
+      - uses: azure/login@v1
+        with:
+          client-id: ${{ secrets.CODE_MIRROR_CLIENT_ID }}
+          tenant-id: ${{ secrets.CODE_MIRROR_TENANT_ID }}
+          subscription-id: ${{ secrets.CODE_MIRROR_SUBSCRIPTION_ID }}
+
+      # Queue a code mirror build in azure devops
+      - name: Queue a build
+        run: |
+          az pipelines build queue --definition-id 16 --project internal --org dnceng --variables BranchToMirror=${GITHUB_HEAD_REF:-${GITHUB_REF#refs/heads/}} GitHubRepo=${{ github.repository_owner }}/${{ github.repository }}
+
+      - name: logout
+        run: |
+          az logout