SDK 4: macOS: tcp connections persist in ESTABLISHED or CLOSE_WAIT state

Using the python client 4 on macOS, tcp connections are not closed leading to performance degradation and file descriptor exhaustion.

The test program run on macOS Monterey with 100 cycles doing basic KV and query operations:

% test/u_test_1.py --host 10.28.1.218

==> Attempt 100:
Creating bucket
Creating index
Upsert 100 test docs
Getting test docs
Getting collection doc count
Getting field from test doc
API call test
open: 0 connections: 1203 fds: 1212 children: 0 CLOSE_WAIT: 392 ESTABLISHED: 811 
====> done <====

The same test on Linux:

% test/u_test_1.py --host 10.28.1.218

==> Attempt 100:
Creating bucket
Creating index
Upsert 100 test docs
Getting test docs
Getting collection doc count
Getting field from test doc
API call test
open: 0 connections: 6 fds: 14 children: 0 ESTABLISHED: 6
====> done <====