Bump celery from 4.4.2 to 4.4.7 in /requirements (#15140)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: William Durand <will+git@drnd.me>

requirements/prod.txt

@@ -146,9 +146,9 @@ boto3==1.14.34 \
     --hash=sha256:726937b33b5bf6036a3889ea6ecad632439d1a53c3dd4497c1c426d348e2dae3 \
     --hash=sha256:781f5d1bbec6c2fe902e8855c1c8a576845eaa06630e817b0e422afa4788620e
 # see last comment - celery is in between boto3 and botocore on purpose.
-celery==4.4.2 \
-    --hash=sha256:108a0bf9018a871620936c33a3ee9f6336a89f8ef0a0f567a9001f4aa361415f \
-    --hash=sha256:5b4b37e276033fe47575107a2775469f0b721646a08c96ec2c61531e4fe45f2a
+celery==4.4.7 \
+    --hash=sha256:a92e1d56e650781fb747032a3997d16236d037c8199eacd5217d1a72893bca45 \
+    --hash=sha256:d220b13a8ed57c78149acf82c006785356071844afe0b27012a4991d44026f9f
 botocore==1.17.34 \
     --hash=sha256:8170f6a236cdfd053275be7b2f1531c90c517d903d38b21d064dc6ba23f20870 \
     --hash=sha256:ff39ec54893397df3c14dd516aedeaff12bb7c363051d8b9bd5fc86bc3e68231

src/olympia/amo/tests/test_send_mail.py

@@ -269,12 +269,6 @@ class TestSendMail(TestCase):
 
     @mock.patch('olympia.amo.tasks.EmailMessage')
     def test_async_will_retry_default(self, backend):
-        # Monkeypatch Celerys ".get()" inside async task error
-        # until https://github.com/celery/celery/issues/4661 (which isn't just
-        # about retries but a general regression that manifests only in
-        # eager-mode) fixed.
-        self.patch('celery.app.task.denied_join_result')
-
         backend.side_effect = self.make_backend_class([True, True, False])
         with self.assertRaises(Retry):
             send_mail('test subject',
@@ -283,12 +277,6 @@ class TestSendMail(TestCase):
 
     @mock.patch('olympia.amo.tasks.EmailMessage')
     def test_async_will_retry(self, backend):
-        # Monkeypatch Celerys ".get()" inside async task error
-        # until https://github.com/celery/celery/issues/4661 (which isn't just
-        # about retries but a general regression that manifests only in
-        # eager-mode) fixed.
-        self.patch('celery.app.task.denied_join_result')
-
         backend.side_effect = self.make_backend_class([True, True, False])
         with self.assertRaises(Retry):
             send_mail('test subject',
@@ -298,14 +286,8 @@ class TestSendMail(TestCase):
 
     @mock.patch('olympia.amo.tasks.EmailMessage')
     def test_async_will_stop_retrying(self, backend):
-        # Monkeypatch Celerys ".get()" inside async task error
-        # until https://github.com/celery/celery/issues/4661 (which isn't just
-        # about retries but a general regression that manifests only in
-        # eager-mode) fixed.
-        self.patch('celery.app.task.denied_join_result')
-
         backend.side_effect = self.make_backend_class([True, True])
-        with self.assertRaises(RuntimeError):
+        with self.assertRaises((Retry, RuntimeError)):
             send_mail('test subject',
                       'test body',
                       max_retries=1,