Snap Store: mark as hidden

to go along with the previous revert commit (to prevent users who have it successfully installed from being prompted for a faulty update) the Snap Store is now hidden due to Bullseye/Buster and older Debian distros (not Ubuntu) not supporting snap features necessary (snapd 2.55.5+ required) to run newer coreXX versions

etc/categories

@@ -165,7 +165,7 @@ Shattered Pixel Dungeon|Games
 Shotwell|Creative Arts
 SimpleScreenRecorder|Multimedia
 Snapdrop|hidden
-Snap Store|Tools
+Snap Store|hidden
 Sonic Pi|Multimedia
 SpeedTest-CLI|Internet
 Sphero SDK|Programming