Enable mypy strict equality checking (#10150)

Fixes one impossible check, but that's it! Closes
https://github.com/certbot/certbot/issues/5649.

certbot/certbot/_internal/main.py

@@ -140,8 +140,6 @@ def _get_and_save_cert(le_client: client.Client, config: configuration.Namespace
                 )
             )
             lineage = le_client.obtain_and_enroll_certificate(domains, certname)
-            if lineage is False:
-                raise errors.Error("Certificate could not be obtained")
             if lineage is not None:
                 hooks.deploy_hook(config, lineage.names(), lineage.live_dir)
                 renewed_domains.extend(domains)

certbot/certbot/_internal/tests/main_test.py

@@ -1410,14 +1410,6 @@ class MainTest(test_util.ConfigTestCase):
         assert 'donate' in mock_register.call_args[0][1]
         assert mock_subscription.called is True
 
-    @mock.patch('certbot._internal.eff.handle_subscription')
-    def test_certonly_new_request_failure(self, mock_subscription):
-        mock_client = mock.MagicMock()
-        mock_client.obtain_and_enroll_certificate.return_value = False
-        with pytest.raises(errors.Error):
-            self._certonly_new_request_common(mock_client)
-        assert mock_subscription.called is False
-
     def _test_renewal_common(self, due_for_renewal, extra_args, log_out=None,
                              args=None, should_renew=True, error_expected=False,
                              quiet_mode=False, expiry_date=datetime.datetime.now(),

tox.ini

@@ -102,7 +102,7 @@ commands = python -m pylint --reports=n --rcfile=.pylintrc {[base]source_paths}
 deps =
     {[testenv]deps}
     -e certbot-ci
-commands = mypy {[base]source_paths}
+commands = mypy {[base]source_paths} --strict-equality
 
 [testenv:isolated-acme]
 description = Tests acme without any Certbot components installed