[IP CLEARANCE] Apache Arrow pyarrow-stubs library

Apache Arrow is receiving a donation of "pyarrow-stubs", a type annotations
library for PyArrow, which is the Python bindings library for the Apache
Arrow C++ implementation.

See also [1].

Please vote to approve this contribution.

This is a lazy consensus majority vote, per the IP clearance process [2],
open for at least 72 hours.

Thanks,
Rok

[1] https://incubator.apache.org/ip-clearance/arrow-pyarrow-stubs-library
[2] https://incubator.apache.org/ip-clearance/