chore: bump swift 6

Signed-off-by: Peefy <[email protected]>

Author: Peefy

.github/workflows/swift-test.yaml

@@ -49,6 +49,6 @@ jobs:
     - name: Setup Swift toolchain
       uses: swift-actions/setup-swift@v2
       with:
-        swift-version: 5
+        swift-version: 6
     - name: Build and run tests
       run: make test