test_force_requests does not complete with UCP protov2 in UCX 1.16+

[pentschev]

The RMA test test_force_requests does not complete as the loop

ucx-py/ucp/_libs/tests/test_rma.py

Lines 208 to 209 in 16667b4

	while self_mem.put_nb(send_msg, _):
	pass

always evaluate to True, thus causing ucp_put_nb to be called forever. This only occurs with UCP protov2 (UCX_PROTO_ENABLE=y) in UCX 1.16 and above.

cc @MattBBaker for awareness.