Prevent last owner from leaving the team

[jankeromnes]

Currently in Teams & Projects:

• Owners can remove Members form the team
• Anyone can leave a team

However, if you're the last Owner of the team and you leave, the team has no owner anymore.

Also, if you're the last person on the team, the team will become empty (and unless someone still has a working invite link, the team name/slug is "burned").

From #4571 (comment):

Some of the possible solutions here:

1. Keep the Leave option as is and on click trigger a toast notification with an error message explaining that you cannot leave because you are the only remaining owner of the team. Needs: Add toast component in notifications #3530.
2. Keep the Leave option as a disabled option (red-300) and show a tooltip on hover explaining why you cannot perform this action. See screenshot A below.
3. Disable the more actions button (gray-400) and show a tooltip on hover. See screenshot B below.

A. Disabled dropdown option	B. Disabled dropdown button

[jldec]

/schedule

[roboquat]

@jldec: Cannot schedule issue - issue does not belong to a team. Use /team to specify one.

In response to this:

/schedule

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[jldec]

/schedule