[Jobs/Serve] Warning for credentials that requires reauth

[Michaelvll]

For cloud credentials like AWS and GCP, they may have expiration, e.g. AWS SSO or gcloud reauth, which will cause significant leakage from the controller for jobs and service if we use these local credentials on the controller. We have multiple users encountered this.

A UX fix should be: we raise an error or print out a warning before starting the job/service if we detect the credential can require reauthorization (or even more aggressively, using the service account for controller by default)

Version & Commit info:

• sky -v: PLEASE_FILL_IN
• sky -c: PLEASE_FILL_IN

[weih1121]

work in progress