Merge pull request #1799 from swiftwasm/maxd/5.3-xcode-gm

Build 5.3 branch with Xcode GM on GitHub Actions

Author: kateinoigakukun

.github/workflows/main.yml

@@ -128,7 +128,7 @@ jobs:
             ${{ runner.os }}-sccache-v10-5.3-
       - name: Build macOS installable archive
         run: |
-          sudo xcode-select --switch /Applications/Xcode_12_beta.app/Contents/Developer/
+          sudo xcode-select --switch /Applications/Xcode_12.app/Contents/Developer/
           ./utils/webassembly/ci.sh
       - name: Upload macOS installable archive
         uses: actions/upload-artifact@v1