Enable Swift 6.3 in CI

Author: x-sheep

.github/workflows/swift.yml

@@ -23,7 +23,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        swift: ["6.1", "6.2"]
+        swift: ["6.1", "6.2", "6.3"]
     steps:
       - uses: actions/checkout@v4
       - name: Build