PY-29371: Sync with teamcity(#176): purge tests on "scenario" call

When some scenarios are skipped due to tags, behave reports their steps but never reports "match" for them.

So, on next "match" stale (ignored actually) step is left on stack and used instead of real one

python/helpers/pycharm/teamcity/jb_behave_formatter.py

@@ -55,6 +55,7 @@ class TeamcityFormatter(Formatter):
         assert isinstance(scenario, Scenario)
         self.__scenario = scenario
         self.__scenario_opened = False
+        self.__steps.clear()
 
     def step(self, step):
         assert isinstance(step, Step)