Merge remote-tracking branch 'origin/main' into dropdowncss

* origin/main: (34 commits)
  Fine tune diff highlighting (#36592)
  Add code editor setting dropdowns (#36534)
  Update to go 1.26.0 and golangci-lint 2.9.0 (#36588)
  Improve diff highlighting (#36583)
  Fix markup code block layout (#36578)
  Remove striped tables in UI (#36509)
  Fix vertical alignment of `.commit-sign-badge` children (#36570)
  Fix mirror sync parser and fix mirror messages (#36504)
  Update JS and PY deps (#36576)
  Add viewer controller for mermaid (zoom, drag) (#36557)
  Misc typescript tweaks (#36523)
  Use full-file highlighting for diff sections (#36561)
  fix(diff): reprocess htmx content after loading more files (#36568)
  [skip ci] Updated translations via Crowdin
  Add wrap to runner label list (#36565)
  fix: add dnf5 command for Fedora in RPM package instructions (#36527)
  Enable pagination on GiteaDownloader.getIssueReactions() (#36549)
  Refactor merge conan and container auth preserve actions taskID (#36560)
  Fix assignee sidebar links and empty placeholder after #32465 refactor (#36559)
  Fix various version parsing problems (#36553)
  ...

web_src/css/modules/dropdown.css

@@ -298,6 +298,10 @@ select.ui.dropdown {
   overflow-wrap: normal;
 }
 
+.ui.selection.dropdown .menu .item:first-of-type {
+  border-radius: 0;
+}
+
 .ui.selection.dropdown:hover {
   border-color: var(--color-input-border-hover);
   box-shadow: none;