modifying sdist test to also test async client_context

Author: sleepyStick

.github/workflows/test-python.yml

@@ -209,4 +209,4 @@ jobs:
             ls
             which python
             pip install -e ".[test]"
-            PYMONGO_MUST_CONNECT=1 pytest -v test/test_client_context.py
+            PYMONGO_MUST_CONNECT=1 pytest -k client_context