fix(ui): improve milestone/project header consistency (#7174)
The related CSS `milestone-card` is used in 3 places:
* global milestone view `/milestones`
* per-repo milestone view
* per-user/org projects view
The first two had gaps too small basically provided by whitespace. The latter was using an unusually large gap via tailwind.
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7174
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: 0ko <0ko@noreply.codeberg.org>
Co-committed-by: 0ko <0ko@noreply.codeberg.org>