Update swift-format version on GitHub Actions

Author: kateinoigakukun

.github/workflows/test.yml

@@ -77,7 +77,7 @@ jobs:
   format:
     runs-on: ubuntu-latest
     container:
-      image: swift:6.0.3
+      image: swift:6.1.2
     steps:
       - uses: actions/checkout@v5
       - run: ./Utilities/format.swift