[orca-list] Please test master for children cache change

[Joanmarie Diggs <jdiggs igalia com>]

Hey all.

Digging further into the problem Burt mentioned with SpaceFM, I tried
disabling pyatspi's caching of children and the submenus are now
speaking for me. If this change does not have any unexpected side
effects, then yay. <smiles> I'm not going to commit it to the stable
branch unless and until we have serious testing. Please beat on master.

Thank you, as always, very much!
--joanie