I'm using openSUSE Tumbleweed w/ snapshot 20240523, Firefox 126.0 (.rpm) and
GNOME 46.1.

On Firefox, the `browser.gnome-search-provider.enabled` parameter is set to
true, while "Firefox" is listed as an enabled search provider on GNOME
(Settings -> Search). The "GNOME shell integration" extension is also enabled,
although I'm not sure it is required. 

Despite my premises, Firefox simply does not appear as a search provider when
trying to search through GNOME. 

I've tried searching for solutions or at least for people with the same issue
and found out this article from a Fedora:
https://mastransky.wordpress.com/2023/10/13/q3-firefox-linux-update/ although I
have no idea how to correctly follow the steps he described. I can only state
that the Mozilla Firefox Search Provider service indeed is _not_ "Activatable".