Make clean-conversation-sidebar safer

[FloEdelmann]

Closes #6116.

Test URLs

• open issue: Every event sandbox#15
• open issue with linked PR: Open issue sandbox#3
• closed issue: 6328 sandbox#56
• draft PR: Open draft PR sandbox#7
• merged PR: PR merged into non-default /2 sandbox#58
• open issue with a milestone and assignee: TS Server: compilerOptionsForInferredProjects does not seem to use plugins property microsoft/TypeScript#18836
• User has triage access
  • issue: Silently fails if token is missing download-directory/download-directory.github.io#39
  • PR: Rewrite with svelte download-directory/download-directory.github.io#37

Screenshot

[fregante]

Thank you for the PR! I don't see how this affects the labels dropdown though, it's not selected by [aria-label="Link issues"] p nor [aria-label="Select reviewers"] > .css-truncate

[FloEdelmann]

I don't see how this affects the labels dropdown though

Indeed, I didn't have to change anything there, because apparently GitHub changed the HTML again. So the feature basically works without changes (apart from the one in dom-utils.ts).

[fregante]

You're right, I dropped the hotfix for now. I suppose this PR is not just "Make feature safer" rather than "Restore it"

I think I've been using the feature in the dev version for a long time and didn't even realize. Maybe because it's not as clean as it used to be, the spacing got a little messed up/wider: