This fixes two memory leaks related to XR action maps.
- Freeing of action maps needs to be moved from wm_xr_exit() to
wm_xr_runtime_data_free() since the runtime may have already been
freed when calling wm_xr_exit().
- Action bindings for action map items were not being freed. This
was mistakenly left out of e844e9e8f3bb since the patch needed to be
updated after d3d4be1db3a0.