CI: Switch to macOS 14 runners and Xcode 15.2

The macOS 14 runners are M1-based and more performant than the macOS 13
runners. They also seems less prone to random failure.

https://github.blog/changelog/2024-01-30-github-actions-macos-14-sonoma-is-now-available/
https://github.blog/changelog/2024-01-30-github-actions-introducing-the-new-m1-macos-runner-available-to-open-source/

.github/workflows/build-project.yaml

@@ -73,7 +73,7 @@ jobs:
 
   macos-build:
     name: Build for macOS 🍏
-    runs-on: macos-13
+    runs-on: macos-14
     needs: check-event
     defaults:
       run:
@@ -90,6 +90,10 @@ jobs:
           : Set Up Environment 🔧
           if (( ${+RUNNER_DEBUG} )) setopt XTRACE
 
+          print '::group::Enable Xcode 15.2'
+          sudo xcode-select --switch /Applications/Xcode_15.2.app/Contents/Developer
+          print '::endgroup::'
+
           print '::group::Clean Homebrew Environment'
           local -a to_remove=()