Use Swift 6.1

Author: dongjoon-hyun

.github/workflows/build_and_test.yml

@@ -51,7 +51,7 @@ jobs:
     - uses: actions/checkout@v4
     - uses: swift-actions/[email protected]
       with:
-        swift-version: "6"
+        swift-version: "6.1"
     - name: Build
       run: swift build -v