sharing: Remove vino preferences

They are unused now.
11 jobs for wip/gnome-remote-desktop in 2 minutes and 54 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #899124
build

00:02:17

 
  Test
passed #899125
test

00:00:37

 
  Manual
manual #899131
allowed to fail manual
armv8
manual #899127
allowed to fail manual
asan
manual #899126
allowed to fail manual
flatpak
manual #899130
allowed to fail manual
msan
manual #899132
allowed to fail manual
ppc64le
manual #899128
allowed to fail manual
tsan
manual #899129
allowed to fail manual
ubsan
 
  Review
manual #899133
allowed to fail manual
review
manual #899134
allowed to fail manual
stop_review