Fix #83819: Toolbar tooltip missing with custom-keymap

When accessing the key-map for tooltips it's important to use
the final "user" keymap, combine from "active" & "default".

Using the active keyconfig would only keys from key-maps that had
been modified.

scripts/startup/bl_ui/space_toolsystem_common.py

@@ -1222,7 +1222,7 @@ def keymap_from_id(context, space_type, idname):
 def _keymap_from_item(context, item):
     if item.keymap is not None:
         wm = context.window_manager
-        keyconf = wm.keyconfigs.active
+        keyconf = wm.keyconfigs.user
         return keyconf.keymaps.get(item.keymap[0])
     return None