Gitea: OAuth2 sign-in reactivates an administrator-deactivated account on auth sources without refresh tokens (incomplete fix of #38009)

Description Gitea's OAuth2 sign-in callback reactivates a deactivated user account IsActive=false when the user signs in through an authentication source that does not issue refresh tokens notably GitHub, and any OIDC/OAuth2 source configured without offlineaccess. PR 38009 added a gate intended ...