logging: Remove unncessary logging patches in backend tests.

There were some tests that had mock patches for logging, although no
logging was actually happening there. This commit removes such patches
in `corporate/tests/test_stripe.py`, `zerver/tests/test_cache.py`,
`zerver/tests/test_queue_worker.py`,
and `zerver/tests/test_signup.py`.

corporate/tests/test_stripe.py

@@ -1674,8 +1674,7 @@ class StripeTest(StripeTestCase):
         self.assertIsNone(plan.next_invoice_date)
         self.assertEqual(plan.status, CustomerPlan.ENDED)
 
-    @patch("corporate.lib.stripe.billing_logger.info")
-    def test_downgrade_free_trial(self, mock_: Mock) -> None:
+    def test_downgrade_free_trial(self) -> None:
         user = self.example_user("hamlet")
 
         free_trial_end_date = self.now + timedelta(days=60)
@@ -1757,8 +1756,7 @@ class StripeTest(StripeTestCase):
         self.assertEqual(old_plan.next_invoice_date, None)
         self.assertEqual(old_plan.status, CustomerPlan.ENDED)
 
-    @patch("corporate.lib.stripe.billing_logger.info")
-    def test_deactivate_realm(self, mock_: Mock) -> None:
+    def test_deactivate_realm(self) -> None:
         user = self.example_user("hamlet")
         with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
             self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, 'token')
@@ -1801,8 +1799,7 @@ class StripeTest(StripeTestCase):
             invoice_plans_as_needed(self.next_year)
         mocked.assert_not_called()
 
-    @patch("corporate.lib.stripe.billing_logger.info")
-    def test_reupgrade_by_billing_admin_after_realm_deactivation(self, mock_: Mock) -> None:
+    def test_reupgrade_by_billing_admin_after_realm_deactivation(self) -> None:
         user = self.example_user("hamlet")
 
         with patch("corporate.lib.stripe.timezone_now", return_value=self.now):

zerver/tests/test_cache.py

@@ -177,10 +177,8 @@ class GetCacheWithKeyDecoratorTest(ZulipTestCase):
             return
 
         hamlet = self.example_user('hamlet')
-        with patch('zerver.lib.cache.logger.warning') as mock_warn:
         with self.assertRaises(NotFoundInCache):
             get_user_function_with_good_cache_keys(hamlet.id)
-            mock_warn.assert_not_called()
 
         cache_set(good_cache_key_function(hamlet.id), hamlet)
         result = get_user_function_with_good_cache_keys(hamlet.id)

zerver/tests/test_queue_worker.py

@@ -424,8 +424,7 @@ class WorkerTest(ZulipTestCase):
             worker.setup()
             with patch('zerver.lib.actions.send_email'), \
                     patch('zerver.worker.queue_processors.send_future_email') \
-                    as send_mock, \
-                    patch('logging.info'):
+                    as send_mock:
                 worker.start()
                 self.assertEqual(send_mock.call_count, 2)
 

zerver/tests/test_signup.py

@@ -556,7 +556,6 @@ class PasswordResetTest(ZulipTestCase):
         # If the domain doesn't match, we do generate an email
         with self.settings(LDAP_APPEND_DOMAIN="example.com"):
             email = self.example_email("hamlet")
-            with patch('logging.info') as mock_logging:
             result = self.client_post('/accounts/password/reset/', {'email': email})
             self.assertEqual(result.status_code, 302)
             self.assertTrue(result["Location"].endswith(