collab_panel: Adjust list item height across the panel (#61466)

Yet another quick follow up to
https://github.com/zed-industries/zed/pull/61397, making sure the height
of each item is consistent. This is particularly important so that the
tree-connecting-lines that show up when you share a project or screen
don't get disconnected.

Release Notes:

- N/A
ff13ee98fdDanilo Leal committed on 7/22/2026, 4:57:34 PM· committed by GitHubparentec3d887
2 files changedLine totals unavailable