Use Xcode 16.1 for UE 5.6 build.

Author: kring

.github/workflows/build.yml

@@ -444,7 +444,7 @@ jobs:
       unreal-engine-zip: "s3://cesium-unreal-engine/5.6.0/UE_56-mac.zip"
       unreal-program-name: "UE_5.6"
       upload-package-base-name: "CesiumForUnreal-56-apple"
-      xcode-version: "15.4"
+      xcode-version: "16.1"
   Combine56:
     runs-on: ubuntu-latest
     needs: [Windows56, Android56, Linux56, Apple56]

.github/workflows/buildApple.yml

@@ -50,10 +50,16 @@ jobs:
           sudo rm -rf /Applications/Xcode_15.2.app
           sudo rm -rf /Applications/Xcode_15.3.0.app
           sudo rm -rf /Applications/Xcode_15.3.app
+          if [ "${{ inputs.xcode-version }}" != "15.4" ]; then
+            sudo rm -rf /Applications/Xcode_15.4.0.app
+            sudo rm -rf /Applications/Xcode_15.4.app
+          fi
           sudo rm -rf /Applications/Xcode_16.0.0.app
           sudo rm -rf /Applications/Xcode_16.0.app
-          sudo rm -rf /Applications/Xcode_16.1.0.app
-          sudo rm -rf /Applications/Xcode_16.1.app
+          if [ "${{ inputs.xcode-version }}" != "16.1" ]; then
+            sudo rm -rf /Applications/Xcode_16.1.0.app
+            sudo rm -rf /Applications/Xcode_16.1.app
+          fi
           sudo rm -rf /Applications/Xcode_16.1_beta.app
           sudo rm -rf /Applications/Xcode_16_beta_6.app
           ls /Applications