Release 1.6

Notable changes:
*  2024-07-03 4a3d940 actionless chore: sync base16 mirror
*  2024-07-03 005251e actionless feat(templates_extra): add qt5ct and qt6ct templates
*  2024-07-03 efdedef actionless feat(templates_extra): add wezterm-themix-edition
*  2024-06-29 9bf09cb actionless chore(templates_extra: gtk4-oodwaita): libadwaita updated to 1.5.2 in Arch
*  2024-06-19 3b05d8b actionless feat(templates_extra: gtk4-oodwaita: themix): style hovered menus/etc
*  2024-06-19 16cbf24 actionless fix(templates_extra: gtk4-oodwaita: pre_build): update code if it's on tag
*  2024-06-19 85a6dec actionless chore(templates_extra: gtk4-oodwaita): pin version to libadwaita 1.5.1 release (current version in Arch Linux repos)
*  2024-06-19 8ab0295 actionless feat(templates_extra): add gtk3-oodwaita (based on adw-gtk3) (fixes: https://github.com/themix-project/themix-gui/issues/167)
*  2024-06-19 126012c actionless chore(templates_extra): add gtk-index.theme template
*  2024-06-19 beba060 actionless chore(templates_extra): rename gtk4 to gtk4-oodwaita
*  2024-06-16 2e056e6 actionless feat(oomox_plugin): hide theme preview in multi-export mode
*  2024-06-16 9704a4f actionless fix(oomox_plugin): don't add options_box twice
*  2024-06-16 f1347b8 actionless feat(oomox_plugin): close dialog after export
*  2024-06-16 41a715f actionless feat(oomox_plugin): add support for <THEME_NAME> in the export config
*  2024-06-13 cf1f5cf actionless feat(oomox_plugin): add support for `override_config` (to load state for multi-export)