chore: cleanup after session finish (#830)

At the end of the test suite file _event is deleted, but _event.lock is
not. This PR fixes it

Author: harshilgajera-crest

pytest_splunk_addon/splunk.py

@@ -1019,3 +1019,5 @@ def pytest_unconfigure(config):
             os.remove(PYTEST_XDIST_TESTRUNUID + "_wait")
         if os.path.exists(PYTEST_XDIST_TESTRUNUID + "_events"):
             os.remove(PYTEST_XDIST_TESTRUNUID + "_events")
+        if os.path.exists(PYTEST_XDIST_TESTRUNUID + "_events.lock"):
+            os.remove(PYTEST_XDIST_TESTRUNUID + "_events.lock")