Fix T61830: Remove option to add new keymap item in search mode

This was not working well, because the search text was removed
after pressing this button. Finding the item that was inserted
was not easy.

Removing the option seems to be the best solution for now.

release/scripts/modules/rna_keymap_ui.py

@@ -346,11 +346,6 @@ def draw_filtered(display_keymaps, filter_type, filter_text, layout):
 
             for kmi in filtered_items:
                 draw_kmi(display_keymaps, kc, km, kmi, col, 1)
-
-            # "Add New" at end of keymap item list
-            col = _indented_layout(layout, 1)
-            subcol = col.split(factor=0.2).column()
-            subcol.operator("preferences.keyitem_add", text="Add New", icon='ADD')
     return True