Run auth qs with Xcode 13 required by Facebook sdk 12.0.1 (#8814)

Author: paulb777

.github/workflows/zip.yml

@@ -137,9 +137,12 @@ jobs:
       signin_secret: ${{ secrets.GHASecretsGPGPassphrase1 }}
       FRAMEWORK_DIR: "Firebase-actions-dir"
       SDK:  "Authentication"
-    runs-on: macOS-10.15
+    runs-on: macos-11
     steps:
     - uses: actions/checkout@v2
+      # Facebook SDK 12.0.1 requires Xcode 13
+    - name: Xcode 13.0
+      run: sudo xcode-select -s /Applications/Xcode_13.0.app/Contents/Developer
     - name: Get framework dir
       uses: actions/download-artifact@v1
       with: