collections.Callable -> collections.abc.Callable
collections.Callable -> collections.abc.Callable

"Deprecated since version 3.3, will be removed in version 3.10"
- https://docs.python.org/3/library/collections.html

marmarek/qubes-core-mgmt-client,marmarek/qubes-core-mgmt-client,marmarek/qubes-core-mgmt-client