Only import MemoryReactor if type-checking in test_scheduler; fix old…

…-deps

tests/appservice/test_scheduler.py

@@ -11,10 +11,10 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from typing import TYPE_CHECKING
 from unittest.mock import Mock
 
 from twisted.internet import defer
-from twisted.internet.testing import MemoryReactor
 
 from synapse.appservice import ApplicationServiceState
 from synapse.appservice.scheduler import (
@@ -31,6 +31,9 @@
 
 from ..utils import MockClock
 
+if TYPE_CHECKING:
+    from twisted.internet.testing import MemoryReactor
+
 
 class ApplicationServiceSchedulerTransactionCtrlTestCase(unittest.TestCase):
     def setUp(self):
@@ -199,7 +202,7 @@ def take_txn(*args, **kwargs):
 
 
 class ApplicationServiceSchedulerQueuerTestCase(unittest.HomeserverTestCase):
-    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer):
+    def prepare(self, reactor: "MemoryReactor", clock: Clock, hs: HomeServer):
         self.scheduler = ApplicationServiceScheduler(hs)
         self.txn_ctrl = Mock()
         self.txn_ctrl.send = simple_async_mock()