mixxx: 2.2.0 -> 2.2.1 (#60632)

* mixxx: 2.2.0 -> 2.2.1

Semi-automatic update generated by
https://github.com/ryantm/nixpkgs-update tools. This update was made
based on information from
https://repology.org/metapackage/mixxx/versions

* mixxx: speedup build with parallel building