On beta sites, when a question is closed without any comments, Community automatically flags it for attention (see here).
These flags have popped up in the flag queue from time to time (whenever this happens).
It seems the text of the flag has recently changed.
You can just leave it until a diamond mod dismisses it; I doubt anyone will be too disturbed by its presence.
Typically the two actions you could take in addition to flagging for attention or as invalid are close and delete:
- Close: It's already closed, so this option is not available.
- Delete: Posts with a score higher than -2 can't be voted for deletion until they've been closed for two days, so this action isn't available.