remove async cleanup of kill all sessions

Author: sleepyStick

test/asynchronous/unified_format.py

@@ -1387,7 +1387,6 @@ async def run_scenario(self, spec, uri=None):
         # transaction (from a test failure) from blocking collection/database
         # operations during test set up and tear down.
         await self.kill_all_sessions()
-        self.addAsyncCleanup(self.kill_all_sessions)
 
         if "csot" in self.id().lower():
             # Retry CSOT tests up to 2 times to deal with flakey tests.

test/unified_format.py

@@ -1374,7 +1374,6 @@ def run_scenario(self, spec, uri=None):
         # transaction (from a test failure) from blocking collection/database
         # operations during test set up and tear down.
         self.kill_all_sessions()
-        self.addCleanup(self.kill_all_sessions)
 
         if "csot" in self.id().lower():
             # Retry CSOT tests up to 2 times to deal with flakey tests.