Swift: Update macOS runner

Author: jketema

.github/workflows/swift.yml

@@ -32,7 +32,7 @@ jobs:
     if: github.repository_owner == 'github'
     strategy:
       matrix:
-        runner: [ubuntu-latest, macos-13-xlarge]
+        runner: [ubuntu-latest, macos-15-xlarge]
       fail-fast: false
     runs-on: ${{ matrix.runner }}
     steps: