Use an existing Kerberos ticket for authn request agains OpenID Connect Provider

[elronzo]

Purpose of the feature (why)

When using kubelogin without a browser one can specify a username and is prompted for a password. ActiveDirectory-integrated systems (through FreeIPA for example) might already have a Kerberos-Ticket that could be used here for the authn request.

Your idea (how)

When using kubelogin without a web browser use existing kerberos tickets a user might already have when logging in to the OpenID Connect Provider .