Try out Ubuntu on arm

Author: fwal

.github/workflows/ci.yml

@@ -26,7 +26,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest]
+        os: [ubuntu-latest, ubuntu-24.04-arm]
         swift: ["6.1"]
     steps:
       - uses: actions/checkout@v4