On a debian based system you can safely neuter geoclue by sending results of it's privacy disrespecting behavior right down to a black hole of nothingness.
Do the following:
Elevate your system privileges via 'sudo' command or log-in as root and do the following:
sudo systemctl disable geoclue.service
sudo systemctl mask geoclue.service
Once done, reboot the host, and when system boots back up, check the output of:
$ sudo systemctl status geoclue.service
Loaded: masked (/dev/null; bad)
Active: inactive (dead)
That's it! No more chatty behavior to Mozilla servers to figure out your geo location.
This does not fix a fundamental issue with gnome foundation and a geoclue developers clueless disregard for a users privacy, as well 'twisting' the users arm in to using gnome+geoclue by default and not providing an option to use gnome-desktop with out this geo-tracing component, but at least you would effectively cripple function of geoclue while continue using gnome-desktop without any issues.