lxqt.lxqt-qtplugin: 0.12.0 -> 0.13.0 (#42984)

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

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

Version release notes (from GitHub):

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/c6381d7911d526753a3a9f2ef17dc34e
- du listing: https://gist.github.com/bc019cd05de1faa42bc8d394d3390267