PYTHON-1181 - Skip parallel_scan tests when connected to mongos

Author: behackett

test/test_collection.py

@@ -1601,6 +1601,7 @@ def test_parallel_scan(self):
  set(range(8000)),
  set(doc['_id'] for doc in docs))
 
+ @client_context.require_no_mongos
  @client_context.require_version_min(3, 3, 10)
  @client_context.require_test_commands
  def test_parallel_scan_max_time_ms(self):