made QuerySet.exists() return a boolean

Author: timgraham

.github/workflows/test-python.yml

@@ -73,6 +73,7 @@ jobs:
           lookup.tests.LookupTests.test_escaping
           model_fields
           or_lookups
+          sessions_tests
 
   docs:
     name: Docs Checks

django_mongodb/compiler.py

@@ -58,7 +58,7 @@ def results_iter(
             yield self._make_result(entity, columns, tuple_expected=tuple_expected)
 
     def has_results(self):
-        return self.get_count(check_exists=True)
+        return bool(self.get_count(check_exists=True))
 
     def _make_result(self, entity, columns, tuple_expected=False):
         """