typing: Add Atspi stubs

[C-Loftus]

Thanks for your work on this library! I generated type stubs for Atspi which is the accessibility client library on Linux. I think it would be useful to add since there is not a lot of tooling around Atspi but it is needed to create assistive technology apps. I think this would make it slightly easier for others to make these sorts of applications.

I generated them like this:

python3 tools/generate.py Atspi 2.0 >> Atspi.pyi

I then verified they work by making a simple app like this

import gi
import typing


gi.require_version("Atspi", "2.0")
from gi.repository import Atspi  

if typing.TYPE_CHECKING:
    import atspi_types

Atspi: "atspi_types" = Atspi 


desktop = Atspi.get_desktop(0)

print(desktop.get_child_count())

[lovetox]

Thanks !