update xcode version

Author: ksiler

.ado/variables/vars.yml

@@ -2,6 +2,6 @@ variables:
   - name: VmImageApple
     value: macos-latest-internal
   - name: xcode_friendly_name
-    value: 'Xcode 15.2'
+    value: 'Xcode 16.2.0'
   - name: xcode_version
-    value: '/Applications/Xcode_15.2.app'
+    value: '/Applications/Xcode_16.2.0.app'