Drop `UserInfo` from logger tagging in webhook. (#2535)
Drop `UserInfo` from logger tagging in webhook. (#2535)

* Drop `UserInfo` from logger tagging in webhook.

This can get big, and can contain mildly sensitive data that some users don't want showing up in logs.

If we keep this, than we should perhaps restrict what we tag to one of the less unbounded fields (e.g. don't include `Extra`)

* Switch UserInfo to contain just Username
knative/pkg,knative/pkg