Fix to start k8s and baremetal clusters at the same time

[daviderli614]

steps:

1. Start the k8s greptimedb cluster gtctl cluster create mycluster
2. After start up is complete, execute kubectl port-forward svc/mycluster-frontend -n default 4003:4003
3. Start the baremetal mode ./bin/gtctl playground, success is as follows:

4. Check the process frontend is not started:

5. Looking at the frontend log, there is error:

2023-10-09T09:54:27.369938Z ERROR greptime: Fatal error occurs! err.msg=Failed to start frontend, source: Failed to start server, source: Tokio IO error: Postgres failed to bind addr 127.0.0.1:4003, source: Address already in use (os error 48) err.code=Internal err.source=Failed to start server, source: Tokio IO error: Postgres failed to bind addr 127.0.0.1:4003, source: Address already in use (os error 48) err.source.sources=[Tokio IO error: Postgres failed to bind addr 127.0.0.1:4003, source: Address already in use (os error 48), Address already in use (os error 48)]

6. Try to connect mysql and dashboard, but fail:

view http://localhost:4000/dashboard/ is ERR_CONNECTION_REFUSED

mysql -h 127.0.0.1 -P 4002
ERROR 2003 (HY000): Can't connect to MySQL server on '127.0.0.1:4002' (61)