gh-111051: [tests] Wait a second to support filesystems with low-reso…

…lution mtime (GH-121959)

Lib/test/test_pdb.py

@@ -3517,10 +3517,12 @@ def test_file_modified_after_execution(self):
             print("hello")
         """
 
+        # the time.sleep is needed for low-resolution filesystems like HFS+
         commands = """
             filename = $_frame.f_code.co_filename
             f = open(filename, "w")
             f.write("print('goodbye')")
+            import time; time.sleep(1)
             f.close()
             ll
         """
@@ -3530,10 +3532,12 @@ def test_file_modified_after_execution(self):
         self.assertIn("was edited", stdout)
 
     def test_file_modified_after_execution_with_multiple_instances(self):
+        # the time.sleep is needed for low-resolution filesystems like HFS+
         script = """
             import pdb; pdb.Pdb().set_trace()
             with open(__file__, "w") as f:
                 f.write("print('goodbye')\\n" * 5)
+                import time; time.sleep(1)
             import pdb; pdb.Pdb().set_trace()
         """