fixes for ext-session-lock-v1

[phragment]

I'm currently looking into ext-session-lock-v1 support in the Qtile wlroots backend. (still work in progress)

The corresponding exceptions I got were:

Exception ignored from cffi callback <function notify_func at 0x7a8e6db49760>:
Traceback (most recent call last):
  File "/usr/lib/python3.12/site-packages/pywayland/server/listener.py", line 35, in notify_func
    data = listener._signal._data_wrapper(data)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/wlroots/wlr_types/session_lock_v1.py", line 48, in __init__
    ptr=ffi.addressof(self._ptr.events.new_surface),
                      ^^^^^^^^^^^^^^^^
ffi.error: struct wlr_session_lock_v1: wrong total size (cdef says 80, but C compiler says 88). fix it or use "...;" as the last field in the cdef for struct wlr_session_lock_v1 to make it flexible

and

Exception ignored from cffi callback <function notify_func at 0x783935ba5760>:
Traceback (most recent call last):
  File "/usr/lib/python3.12/site-packages/pywayland/server/listener.py", line 35, in notify_func
    data = listener._signal._data_wrapper(data) 
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/wlroots/wlr_types/session_lock_v1.py", line 68, in __init__
    self.map_event = Signal(ptr=ffi.addressof(self._ptr.events.map))
                                              ^^^^^^^^^^^^^^^^^^^^
AttributeError: cdata 'struct $46' has no field 'map'

[heuer]

+1

[bodograumann]

Is there anything we can do to get this merged, @flacjacket ?