Update Symbol Collision test Xcode (#14431)

Author: paulb777

.github/workflows/symbolcollision.yml

@@ -20,7 +20,7 @@ jobs:
   installation-test:
     # Don't run on private repo unless it is a PR.
     if: (github.repository == 'Firebase/firebase-ios-sdk' && github.event_name == 'schedule') || github.event_name == 'pull_request'
-    runs-on: macos-14
+    runs-on: macos-15
 
     steps:
     - uses: actions/checkout@v4
@@ -31,7 +31,7 @@ jobs:
     - name: Setup Bundler
       run: scripts/setup_bundler.sh
     - name: Xcode
-      run: sudo xcode-select -s /Applications/Xcode_15.3.app/Contents/Developer
+      run: sudo xcode-select -s /Applications/Xcode_16.2.app/Contents/Developer
     - name: Prereqs
       run: scripts/install_prereqs.sh SymbolCollision iOS
     - name: Build