Some pandas io tests hang when run sequentially, put pass when run individually. One just hangs

[radhikaj]

/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_user_agent.py hangs when run with run-one
The following tests pass when run individually, but hang when run sequentially
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_stata.py
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_sql.py
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_pickle.py
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_html.py
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_s3.py
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_common.py
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_gcs.py
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_fsspec.py
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_date_converters.py
/usr/local/lib/python3.9/site-packages/pandas/tests/io/test_compression.py
/usr/local/lib/python3.9/site-packages/pandas/tests/internals/test_managers.py

See PR #1192 for more details