Use newer Xcode

Author: jberkel

.github/workflows/build.yml

@@ -5,15 +5,9 @@ env:
   IOS_VERSION: "17.2"
 jobs:
   build:
-    runs-on: macos-14
+    runs-on: macos-15
     steps:
     - uses: actions/checkout@v2
-    - name: "Select Xcode"
-      # Currently only works with Xcode 14.2:
-      # https://github.com/CocoaPods/CocoaPods/issues/11839
-      run: |
-        xcode-select -p
-        sudo xcode-select -s /Applications/Xcode_15.3.app/Contents/Developer
     - name: "Lint"
       run: make lint
     - name: "Run tests (PACKAGE_MANAGER_COMMAND: test)"