clutter/stage: Use own list of pointer devices to find updated devices

Due to a few reasons currently the updating of input devices after stage
relayouts isn't working right now. Since we now have a list of pointer
devices in ClutterStage, we can simply use that list and can avoid
asking the input thread. Also we no longer need to check whether the
devices are pointer devices, since our list only consists of pointer
devices.

So switch to ClutterStages private list of pointer devices, which also
includes the core pointer (as opposed to the list returned by
clutter_seat_peek_devices()). This fixes picking after relayouts.

Note that this doesn't catch every possible change that might need a
repick, actors might also need a repick after transformation changes or
in case their custom clip has been changed.
13 jobs for fix-updating-devices-stage
Status Job ID Name Coverage
  Review
manual #1047720
manual
check-commit-log
manual #1047721
manual
check-merge-request
 
  Prepare
created #1047723
aarch64
build-fedora-container@aarch64
created #1047722
build-fedora-container@x86_64
 
  Build
created #1047725
aarch64
build-mutter@aarch64
created #1047724
build-mutter@x86_64
created #1047727
build-without-native-backend-and-wayland@x86_64
created #1047726
build-without-opengl-and-glx@x86_64
 
  Test
created #1047730
can-build-gnome-shell@x86_64
created #1047729
aarch64
test-mutter@aarch64
created #1047728
test-mutter@x86_64
 
  Coverage
created #1047732
aarch64
test-mutter-coverage@aarch64
created #1047731
test-mutter-coverage@x86_64