fix(tests): update Swoole version to 5.1.6 in workflow configuration

Author: huangdijia

.github/workflows/tests.yaml

@@ -49,7 +49,7 @@ jobs:
       matrix:
         os: [ubuntu-latest]
         php: ['8.3', '8.2', '8.1']
-        swoole: ['5.1.5', '6.0.0']
+        swoole: ['5.1.6', '6.0.0']
         # exclude:
         #   - php: '8.3'
         #     swoole: '5.0.3'