Fix the case when abstract method could be overridden by ancestor field.

PY-26300 fixed.

python/testData/inspections/PyAbstractClassInspection/overriddenAsFieldInAncestor.py

@@ -0,0 +1,13 @@
+from abc import ABCMeta, abstractmethod
+
+class BaseClass(metaclass=ABCMeta):
+    @property
+    @abstractmethod
+    def abstract_property(self):
+        pass
+
+class SubClass(BaseClass):
+    abstract_property = 5
+
+class SubSubClass(SubClass):
+    pass