community/phosh: give preference to Phosh in DesktopNames
Since gnome-session 45.0, which is a Phosh dependency, GNOME also ships a portal configuration. Since XDG_CURRENT_DESKTOP is derived from that variable, having GNOME first has the consequence of using the GNOME instead of the Phosh config.
Effectively, we've regressed https://gitlab.com/postmarketOS/pmaports/-/issues/2263
This commit fixes it