Did you see the post above on gramps-web-desktop?
It is a pip-installable package with the frontend (repo has a build command). It should be possible to use both gramps and gramps-web-api without any Gtk or docker complexities. But the core gramps code still brings in some Gtk/Gdk items unnecessarily. gramps-web-api used to require a 6 GB download, but now 2.7.0 can be used without the AI stuff (except still needs torch until a new version is released).