[3.12] gh-106197: Deduplicate tests in test_buffer (GH-106198) (#106206)

gh-106197: Deduplicate tests in `test_buffer` (GH-106198)
(cherry picked from commit c283a0c)

Co-authored-by: Nikita Sobolev <[email protected]>

Author: miss-islington

Lib/test/test_buffer.py

@@ -4718,7 +4718,7 @@ def __buffer__(self, flags):
         with self.assertRaises(ValueError):
             c.buffer.tobytes()
 
-    def test_multiple_inheritance_buffer_last(self):
+    def test_multiple_inheritance_buffer_last_raising(self):
         class A:
             def __buffer__(self, flags):
                 raise RuntimeError("should not be called")