adapta-gtk-theme: 3.93.1.22 -> 3.93.1.28 (#43056)

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/adapta-gtk-theme/versions.

Version release notes (from GitHub):
* Added some workarounds for Pixel-saver applet in Budgie (Gtk+ 3.2x/4.0).
* Dropped some outdated styling in FirefoxQuantum (Gtk+ 3.2x/4.0).

These checks were done:

- built on NixOS

- 0 of 0 passed binary check by having a zero exit code.
- 0 of 0 passed binary check by having the new version present in output.
- directory tree listing: https://gist.github.com/2a01274ab6cfba1470a7eec4fd70802c
- du listing: https://gist.github.com/9c89b76ba6d49d6056387e6e044f346f