use xcode 16 for objc build

Author: morganchen12

.github/workflows/storage.yml

@@ -32,6 +32,7 @@ jobs:
         uses: actions/checkout@master
       - name: Build ObjC snippets
         run: |
+          sudo xcode-select -switch /Applications/Xcode_16.1.app/Contents/Developer
           cd storage
           xcodebuild -project StorageReference.xcodeproj clean build -scheme StorageReference -destination "${destination}" CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO
         env: