/usr/share/geany-plugins/ is in geany-plugin-lua 1.23+dfsg-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/geany-plugins/geanylua/
/usr/share/geany-plugins/geanylua/dialogs/
/usr/share/geany-plugins/geanylua/dialogs/basic-dialogs.lua
/usr/share/geany-plugins/geanylua/dialogs/complex-dialog.lua
/usr/share/geany-plugins/geanylua/edit/
/usr/share/geany-plugins/geanylua/edit/calculator.lua
/usr/share/geany-plugins/geanylua/edit/lua-replace.lua
/usr/share/geany-plugins/geanylua/edit/proper-case.lua
/usr/share/geany-plugins/geanylua/edit/reverse.lua
/usr/share/geany-plugins/geanylua/edit/right-trim.lua
/usr/share/geany-plugins/geanylua/edit/select-block.lua
/usr/share/geany-plugins/geanylua/info/
/usr/share/geany-plugins/geanylua/info/about.lua
/usr/share/geany-plugins/geanylua/info/app-information.lua
/usr/share/geany-plugins/geanylua/info/file-information.lua
/usr/share/geany-plugins/geanylua/info/list-open-files.lua
/usr/share/geany-plugins/geanylua/info/show-filename.lua
/usr/share/geany-plugins/geanylua/scripting/
/usr/share/geany-plugins/geanylua/scripting/help.lua
/usr/share/geany-plugins/geanylua/scripting/open-script.lua
/usr/share/geany-plugins/geanylua/scripting/rebuild-menu.lua
/usr/share/geany-plugins/geanylua/scripting/show-examples.lua
/usr/share/geany-plugins/geanylua/work/
/usr/share/geany-plugins/geanylua/work/01.edit-test-script.lua
/usr/share/geany-plugins/geanylua/work/02.run-test-script.lua
/usr/share/geany-plugins/geanylua/work/03.install-test-script.lua