Re-enable Xcode check as 12.2 Beta 3 is available

Hopefully this will allow us to diagnose incompatibility issues in the future quickly.

Author: MaxDesiatov

.github/workflows/main.yml

@@ -128,8 +128,6 @@ jobs:
         run: |
           sudo xcode-select --switch /Applications/Xcode_12.2.0.app/Contents/Developer/
           ./utils/webassembly/ci.sh
-        env:
-          SKIP_XCODE_VERSION_CHECK: 1
       - name: Upload macOS installable archive
         uses: actions/upload-artifact@v1
         with: