Pin CodeQL to Xcode 15.4

Author: offyotto

.github/workflows/codeql.yml

@@ -23,13 +23,19 @@ concurrency:
 jobs:
   analyze-swift:
     name: Analyze Swift
-    runs-on: macos-latest
+    runs-on: macos-14
     timeout-minutes: 45
 
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      - name: Select Xcode 15.4
+        run: |
+          set -euo pipefail
+          sudo xcode-select -s /Applications/Xcode_15.4.app/Contents/Developer
+          xcodebuild -version
+
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v4
         with: