DOC: fix typo in deprecation warning (#14521)

I'm sorry about the ridiculous level of triviality here, but just
reading the message it wasn't clear at first if I need to import from
`IPython` or from `IPython.display` and naturally I went with the wrong
one at first.

(My line was `from IPython.core.display import display`, so it wasn't
obvious at first if the 'display' in the deprecation message was for the
function or the module.)

IPython/core/display.py

@@ -41,7 +41,11 from warnings import warn
 
 def __getattr__(name):
     if name in _deprecated_names:
-        warn(f"Importing {name} from IPython.core.display is deprecated since IPython 7.14, please import from IPython display", DeprecationWarning, stacklevel=2)
+        warn(
+            f"Importing {name} from IPython.core.display is deprecated since IPython 7.14, please import from IPython.display",
+            DeprecationWarning,
+            stacklevel=2,
+        )
         return getattr(display_functions, name)
 
     if name in globals().keys():