mate.mate-menus: 1.20.0 -> 1.20.1

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

This update was made based on information from https://repology.org/metapackage/mate-menus/versions.

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.
- found 1.20.1 with grep in /nix/store/9hfl9953if9wmc6y8zyw5wmx61ngi9lh-mate-menus-1.20.1
- directory tree listing: https://gist.github.com/c04722d4564c89227f336ed797444a78
- du listing: https://gist.github.com/9a8dc65709b3969980df3dc3b8ffcc4b