swift_tests is failing on CI

The exact failure can be found in https://github.com/envoyproxy/envoy-mobile/pull/1796/checks?check_run_id=3588284340#step:5:1953

The specific error is:
```
Warning: 13 14:58:21.103][136965][warning][config] [external/envoy/source/server/listener_impl.cc:855] reuse_port was configured for TCP listener 'fake_remote_listener' and is being force disabled because Envoy is not running on Linux. See the documentation for more information.
Error: 9-13 14:58:21.132][136965][error][config] [external/envoy/source/server/listener_manager_impl.cc:1010] listener 'fake_remote_listener' failed to bind or apply socket options: cannot bind '127.0.0.1:10101': Address already in use
```

Which is related to how Envoy is configured for MacOS builds.