[3.13] gh-122087: Restore ismethoddescriptor() and isroutine() for partial objects (GH-122218)

Now they return False again.

Lib/inspect.py

@@ -325,6 +325,11 @@ def ismethoddescriptor(object):
     if isclass(object) or ismethod(object) or isfunction(object):
         # mutual exclusion
         return False
+    if isinstance(object, functools.partial):
+        # Lie for children.  The addition of partial.__get__
+        # doesn't currently change the partial objects behaviour,
+        # not counting a warning about future changes.
+        return False
     tp = type(object)
     return (hasattr(tp, "__get__")
             and not hasattr(tp, "__set__")