bug#63425: GNOME tracker does not work with tracker-miners

[Sughosha via Bug reports for GNU Guix]

GNOME "tracker" is built with "libexecdir" in its own prefix in the store and 
"tracker-miners" in its own. The problem is that "tracker" does not have access 
to the executable files in the "libexecdir" of "tracker-miners", so commands 
like "tracker3 extract file.flac" does not work. Due to this problem GNOME 
Music cannot list FLAC files (I don't know how it listed my MP3 file). As per 
this issue <https://gitlab.gnome.org/GNOME/gnome-music/-/issues/522>, "tracker3 
extract" should work for GNOME Music to show FLAC files.