Prevent double close comments

[qwerty287]

Feature Description

Gitea should prevent close comments if the issue is already closed (just don't add another comment). This happens while merging a PR with squash merge - one close comment comes from the PR desc (close #...) and one from the merge commit if the PR desc is also the commit message.

Screenshots

This example comes from https://codeberg.org/gitnex/GitNex/issues/985#event-291274

[wxiaoguang]

That's a long story and duplicated of #17111
We could close this one

update: this seems a new problem.

[wxiaoguang]

Hmm ... maybe we could do some backend work for the Close action only.