Add regression test for no-member with empty AnnAssign (#7632)

Author: cdce8p

tests/functional/r/regression_02/regression_no_member_7631.py

@@ -0,0 +1,16 @@
+"""Regression test from https://github.com/PyCQA/pylint/issues/7631
+The following code should NOT raise no-member.
+"""
+# pylint: disable=missing-docstring,too-few-public-methods
+
+class Base:
+    attr: int = 2
+
+class Parent(Base):
+    attr: int
+
+class Child(Parent):
+    attr = 2
+
+    def __init__(self):
+        self.attr = self.attr | 4