Stop page reload when hiding the labels dropdown

[davidglezz]

When displaying the labels dropdown of labels and selecting none, the page reloads.

The expected behavior is that if there are no changes do not reload the page. I realized when I was editing an issue and displayed the menu and I lost all the changes.

• Gitea version: 1.9 an 1.10
• Tested on Google Chrome

[silverwind]

Page reloads should be eliminated, they are always disruptive and unneccessary.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. I am here to help clear issues left open even if solved or waiting for more insight. This issue will be closed if no further activity occurs during the next 2 weeks. If the issue is still valid just add a comment to keep it alive. Thank you for your contributions.

[stale]

This issue has been automatically closed because of inactivity. You can re-open it if needed.

[wxiaoguang]

Fixed by #23014 (a quick fix)