improvement: If assign metalake owner to a user who isn't in the IDP, then no one can access the metalake again

### Version

main branch

### Describe what's wrong

I use Keycloak as the IDP for gravitino, after assign the metalake owner to a wrong user who is not in the IDP, then I don't have a way to assign back because no legal user have the set owner permission.

### Error message and/or stacktrace

N/A

### How to reproduce

1. use Keycloak as the IDP for gravitino,
2. assign the metalake owner to a wrong user who is not in the IDP

### Additional context

_No response_