PYTHON-3142 Stop using $where in test_maxConnecting (#886)

(cherry picked from commit 8496ed4)

Author: ShaneHarvey

test/test_pooling.py

@@ -378,12 +378,14 @@ def test_checkout_more_than_max_pool_size(self):
     def test_maxConnecting(self):
         client = rs_or_single_client()
         self.addCleanup(client.close)
+        self.client.test.test.insert_one({})
+        self.addCleanup(self.client.test.test.delete_many, {})
         pool = get_pool(client)
         docs = []
 
         # Run 50 short running operations
         def find_one():
-            docs.append(client.test.test.find_one({"$where": delay(0.001)}))
+            docs.append(client.test.test.find_one({}))
 
         threads = [threading.Thread(target=find_one) for _ in range(50)]
         for thread in threads:
@@ -394,9 +396,8 @@ def find_one():
         self.assertEqual(len(docs), 50)
         self.assertLessEqual(len(pool.sockets), 50)
         # TLS and auth make connection establishment more expensive than
-        # the artificially delayed query which leads to more threads
-        # hitting maxConnecting. The end result is fewer total connections
-        # and better latency.
+        # the query which leads to more threads hitting maxConnecting.
+        # The end result is fewer total connections and better latency.
         if client_context.tls and client_context.auth_enabled:
             self.assertLessEqual(len(pool.sockets), 30)
         else: