gh-116780: Fix test_inspect in -OO mode (#116788)

Author: sobolevn

Lib/test/test_inspect/test_inspect.py

@@ -991,7 +991,11 @@ def test_class_decorator(self):
         self.assertSourceEqual(mod2.cls196, 194, 201)
         self.assertSourceEqual(mod2.cls196.cls200, 198, 201)
 
+    @support.requires_docstrings
     def test_class_inside_conditional(self):
+        # We skip this test when docstrings are not present,
+        # because docstrings are one of the main factors of
+        # finding the correct class in the source code.
         self.assertSourceEqual(mod2.cls238.cls239, 239, 240)
 
     def test_multiple_children_classes(self):
@@ -5284,6 +5288,7 @@ def func(*args, **kwargs):
         with self.assertRaises(ValueError):
             inspect.signature(func)
 
+    @support.requires_docstrings
     def test_base_class_have_text_signature(self):
         # see issue 43118
         from test.typinganndata.ann_module7 import BufferedReader