Rigify could not call function unregister of feature set GameRig

[ericwomer]

OS: KUbuntu 23.04
Blender: 3.6.5
GameRig: 3.5

Trying to unregister GameRig until issue #29 is fixed and I get this error.

Rigify Error: Could not call function 'unregister' of feature set 'GameRig_0_3_5': exception occurred.

Traceback (most recent call last):
  File "/home/eric/.local/share/Blender/blender-3.6.5-linux-x64/3.6/scripts/addons/rigify/feature_set_list.py", line 108, in call_function_safe
    return func(*(args or []), **(kwargs or {}))
  File "/home/eric/.config/blender/3.6/scripts/rigify/GameRig_0_3_5/__init__.py", line 46, in unregister
    m.unregister()
  File "/home/eric/.config/blender/3.6/scripts/rigify/GameRig_0_3_5/ui.py", line 487, in unregister
    bpy.types.DATA_PT_rigify_buttons.remove(draw_gamerig_rigify_button)
AttributeError: 'module' object has no attribute 'DATA_PT_rigify_buttons'