Fix Limit 0 QuerySet Empty List (#767)

* fix: debug condition check not none limit count

* test: write a test for check zero limit empty list

* fix: debug assert check empty list with is keyword

tests/test_queries/test_pagination.py

@@ -47,6 +47,18 @@ def create_test_database():
     metadata.drop_all(engine)
 
 
+@pytest.mark.asyncio
+async def test_limit_zero():
+    async with database:
+        async with database.transaction(force_rollback=True):
+            for i in range(5):
+                await Car(name=f"{i}").save()
+
+            cars = await Car.objects.limit(0).all()
+            assert cars == []
+            assert len(cars) == 0
+
+
 @pytest.mark.asyncio
 async def test_pagination_errors():
     async with database: