Build/NR: Update to use Xcode 16.4

Author: jbe2277

.github/workflows/NewsReader.CI.yml

@@ -141,7 +141,7 @@ jobs:
 
     - name: ⚙️ Set Xcode version
       run: |
-        XCODE_ROOT=/Applications/Xcode_16.3.app
+        XCODE_ROOT=/Applications/Xcode_16.4.app
         echo "MD_APPLE_SDK_ROOT=$XCODE_ROOT" >> $GITHUB_ENV       # set environment variable to specify Xcode for Mono and Xamarin
         sudo xcode-select -s $XCODE_ROOT