Add Arch package registry (#32692)

Close #25037
Close #31037

This PR adds a Arch package registry usable with pacman.

![grafik](https://github.com/user-attachments/assets/81cdb0c2-02f9-4733-bee2-e48af6b45224)

Rewrite of #25396 and #31037. You can follow [this
tutorial](https://wiki.archlinux.org/title/Creating_packages) to build a
package for testing.

Docs PR: https://gitea.com/gitea/docs/pulls/111

Co-authored-by: [d1nch8g@ion.lc](mailto:d1nch8g@ion.lc)
Co-authored-by: @ExplodingDragon

---------

Co-authored-by: dancheg97 <dancheg97@fmnx.su>
Co-authored-by: dragon <ExplodingFKL@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

web_src/css/base.css

@@ -1386,7 +1386,7 @@ table th[data-sortt-desc] .svg {
 .flex-text-block {
   display: flex;
   align-items: center;
-  gap: .25rem;
+  gap: .5rem;
   min-width: 0;
 }