Various UI fixes (#25264)

Numerous small UI fixes:

- Fix double border in collaborator list
- Fix system notice table background
- Mute links in repo and org lists
- Downsize projects edit buttons
- Improve milestones and project list rendering
- Condense milestone list entry to a single line of "metas"
- Mute ".." button in repo files list

web_src/css/base.css

@@ -869,6 +869,13 @@ a.label,
   border-color: var(--color-secondary);
 }
 
+.ui.table > tfoot > tr > th,
+.ui.table > tfoot > tr > td {
+  border-color: var(--color-secondary);
+  background: var(--color-box-body);
+  color: var(--color-text);
+}
+
 img.ui.avatar,
 .ui.avatar img,
 .ui.avatar svg {

web_src/css/repo.css

@@ -1947,10 +1947,6 @@
   line-height: 2em;
 }
 
-.repository.settings.collaboration .collaborator.list > .item:not(:last-child) {
-  border-bottom: 1px solid var(--color-secondary);
-}
-
 .repository.settings.collaboration #repo-collab-form #search-user-box .results {
   left: 7px;
 }

web_src/css/shared/issuelist.css

@@ -135,10 +135,6 @@
   margin-right: -4px;
 }
 
-.issue.list > .item .desc .overdue {
-  color: var(--color-red);
-}
-
 .issue.list .branches {
   display: inline-flex;
   padding: 0 4px;

web_src/css/shared/milestone.css

@@ -44,10 +44,6 @@
   gap: 8px;
 }
 
-.milestone-toolbar .group .overdue {
-  color: var(--color-red);
-}
-
 .milestone-toolbar .group > a {
   font-size: 15px;
   color: var(--color-text-light-2);