Update swift.yml

Author: tomasf

.github/workflows/swift.yml

@@ -13,7 +13,7 @@ jobs:
   build:
     strategy:
       matrix:
-        os: [macos-14, ubuntu-latest, windows-latest]
+        os: [macos-15, ubuntu-latest, windows-latest]
 
     runs-on: ${{ matrix.os }}