Linear returns an issue's comments newest first and getIssueComments
passed that order through, so the activity feed showed the newest comment
on top while comments posted from Orca were appended at the bottom and
jumped to the top on reload. Sort by createdAt, oldest first, like the
GitLab notes path does.
Fixes#25573
Co-authored-by: Neil <4138956+nwparker@users.noreply.github.com>