gh-121300: Add replace to copy.__all__ (#121302)

Lib/copy.py

@@ -4,8 +4,9 @@ Interface summary:
 
         import copy
 
-        x = copy.copy(y)        # make a shallow copy of y
-        x = copy.deepcopy(y)    # make a deep copy of y
+        x = copy.copy(y)                # make a shallow copy of y
+        x = copy.deepcopy(y)            # make a deep copy of y
+        x = copy.replace(y, a=1, b=2)   # new object with fields replaced, as defined by `__replace__`
 
 For module specific errors, copy.Error is raised.
 
@@ -56,7 +57,7 @@ class Error(Exception):
     pass
 error = Error   # backward compatibility
 
-__all__ = ["Error", "copy", "deepcopy"]
+__all__ = ["Error", "copy", "deepcopy", "replace"]
 
 def copy(x):
     """Shallow copy operation on arbitrary Python objects.