Add server stand up test as part of MLX CI

Hi @ckadner sorry I didn't have time to recompile the server for every PR. Right now our CI is only catching build errors but we don't have any test to catch runtime errors. Maybe we can add a simple test just to start the server to make sure nothing is crashing the server startup? This way we don't accidentally merged critical bugs that crashes our server startup.

Originally posted by @Tomcli in https://github.com/machine-learning-exchange/mlx/issues/205#issuecomment-920338732