fix: add no branch pragma for task group in test_session.py

Author: felixweinberger

tests/shared/test_session.py

@@ -104,7 +104,7 @@ async def make_request(session: ClientSession):
     async with transport.connect() as (read_stream, write_stream):
         async with ClientSession(read_stream=read_stream, write_stream=write_stream) as session:
             await session.initialize()
-            async with anyio.create_task_group() as tg:
+            async with anyio.create_task_group() as tg:  # pragma: no branch
                 tg.start_soon(make_request, session)
 
                 # Wait for the request to be in-flight