Fix pyplot.set_loglevel not appearing in docs.

As the comment says, it's in that file for documentation purposes, but
`functools.wraps` copies `__module__`, so it never appears in `pyplot`
docs.

Author: QuLogic

doc/missing-references.json

@@ -1270,9 +1270,6 @@
     "print_xyz": [
       "lib/matplotlib/backends/backend_template.py:docstring of matplotlib.backends.backend_template:22"
     ],
-    "pyplot.set_loglevel": [
-      "doc/users/prev_whats_new/whats_new_3.1.0.rst:374"
-    ],
     "rrulewrapper": [
       "lib/matplotlib/dates.py:docstring of matplotlib.dates:143"
     ],
@@ -1339,4 +1336,4 @@
       "lib/mpl_toolkits/mplot3d/axes3d.py:docstring of mpl_toolkits.mplot3d.axes3d.Axes3D.get_ylim3d:24"
     ]
   }
-}
+}

lib/matplotlib/pyplot.py

@@ -186,7 +186,7 @@ def uninstall_repl_displayhook():
 draw_all = _pylab_helpers.Gcf.draw_all
 
 
-@functools.wraps(matplotlib.set_loglevel)
+@_copy_docstring_and_deprecators(matplotlib.set_loglevel)
 def set_loglevel(*args, **kwargs):  # Ensure this appears in the pyplot docs.
     return matplotlib.set_loglevel(*args, **kwargs)