[Firestore] Update CI tests to Xcode 16.3 (#14801)

Author: paulb777

.github/workflows/firestore.yml

@@ -401,7 +401,7 @@ jobs:
     - name: Setup Bundler
       run: ./scripts/setup_bundler.sh
     - name: Xcode
-      run: sudo xcode-select -s /Applications/Xcode_16.2.app/Contents/Developer
+      run: sudo xcode-select -s /Applications/Xcode_16.3.app/Contents/Developer
 
     - name: Pod lib lint
       # TODO(#9565, b/227461966): Remove --no-analyze when absl is fixed.
@@ -494,19 +494,19 @@ jobs:
             xcode: Xcode_16.2
             target: iOS
           - os: macos-15
-            xcode: Xcode_16.2
+            xcode: Xcode_16.3
             target: iOS
           - os: macos-15
-            xcode: Xcode_16.2
+            xcode: Xcode_16.3
             target: tvOS
           - os: macos-15
-            xcode: Xcode_16.2
+            xcode: Xcode_16.3
             target: macOS
           - os: macos-15
-            xcode: Xcode_16.2
+            xcode: Xcode_16.3
             target: catalyst
           - os: macos-15
-            xcode: Xcode_16.2
+            xcode: Xcode_16.3
             target: visionOS
     runs-on: ${{ matrix.os }}
     env: