How to use vertica-sql-go with kerberos ?

No
It is not there
vertica-sql-go is an open source - go ahead and add Kerberos functionality.
When you will be doing that, please also add OATH2 together with Kerberos.

Sergey,
I passed this forum link on to the team who develops/maintains the sql go driver. Same group who we asked for oauth2 so we could solve the Grafana plugin hard coded user in the data source vs dynamic based on Grafana user. If possible vcould you add an issue to the sql go driver repo on github like you did for oauth2? Customer requests pull more weight than internals.
Regards,

Yes, request for OATH2 is in vertica-sql-go