Readd action set sync SystemSet

Signed-off-by: Schmarni <marnistromer@gmail.com>

crates/bevy_openxr/src/openxr/action_set_syncing.rs

@@ -2,12 +2,15 @@ use crate::session::OxrSession;
 use bevy::prelude::*;
 use bevy_xr::session::session_running;
 
+#[derive(SystemSet, Debug, Hash, PartialEq, Eq, Clone, Copy)]
+pub struct ActionSetSyncSet;
+
 impl Plugin for OxrActionSyncingPlugin {
     fn build(&self, app: &mut App) {
         app.add_event::<OxrSyncActionSet>();
         app.add_systems(
             PreUpdate,
-            sync_sets.run_if(session_running), // .in_set(OxrPreUpdateSet::SyncActions),
+            sync_sets.in_set(ActionSetSyncSet).run_if(session_running), // .in_set(OxrPreUpdateSet::SyncActions),
         );
     }
 }