ci: Enable gl-renderer in weston for wayland testing

The weston headless backend defaults to gl-renderer disabled, which
exposes a different set of globals and clients may fall back to software
rendering.
Enable gl-renderer so that clients use the hardware drivers.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Acked-by: David Heidelberg <david.heidelberg@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20391>

.gitlab-ci/common/init-stage2.sh

@@ -145,7 +145,7 @@ if [ -n "$HWCI_START_WESTON" ]; then
   export XDG_RUNTIME_DIR=/run/user
   mkdir -p $XDG_RUNTIME_DIR
 
-  weston -Bheadless-backend.so -Swayland-0 &
+  weston -Bheadless-backend.so --use-gl -Swayland-0 &
   export WAYLAND_DISPLAY=wayland-0
   sleep 1
 fi