2.4.2

- Use ayatana-indicator instead of indicator
- Update copyright year
- Remove deprecated project files
- build: Add GLib requirement
- Use xfce_panel_plugin_popup_menu() when possible
- Fix unused variable
- Update `.gitignore`
- Use icon names instead of pixbufs in dialog treeview
- Use "logo-icon-name" instead of "logo" in about dialog
- Override fatal log level only in debug mode
- Update COPYING See also:
https://gitlab.xfce.org/apps/xfce4-taskmanager/-/issues/49
- Translation Updates:
  Albanian, Amharic, Arabic, Basque, Belarusian, Bulgarian, Catalan,
  Chinese (China), Chinese (Taiwan), Croatian, Czech, Danish, Dutch,
  Eastern Armenian, English (Australia), English (Canada), English
  (United Kingdom), Finnish, French, Galician, German, Greek, Hebrew,
  Hungarian, Icelandic, Indonesian, Interlingue, Italian, Japanese,
  Korean, Lithuanian, Malay, Norwegian Bokmål, Occitan (post 1500),
  Polish, Portuguese, Portuguese (Brazil), Romanian, Russian, Serbian,
  Slovak, Slovenian, Spanish, Swedish, Thai, Turkish, Ukrainian