Fix #129819: GPv3: Context menu for all paint tools

Previously the `W` menu was only available for brush tools (brush and
eraser), it should be available to all tools, thus putting the key map
registering function into `km_grease_pencil_paint_mode`.

Pull Request: https://projects.blender.org/blender/blender/pulls/129837

scripts/presets/keyconfig/keymap_data/blender_default.py

@@ -3788,6 +3788,8 @@ def km_grease_pencil_paint_mode(params):
             "VIEW3D_AST_brush_gpencil_paint",
             {"type": 'SPACE', "value": 'PRESS', "shift": True}
         ),
+
+        *_template_items_context_panel("VIEW3D_PT_greasepencil_draw_context_menu", params.context_menu_event),
     ])
 
     return keymap
@@ -3820,7 +3822,6 @@ def km_grease_pencil_brush_stroke(_params):
          {"properties": [("scalar", 0.9)]}),
         ("brush.scale_size", {"type": 'RIGHT_BRACKET', "value": 'PRESS', "repeat": True},
          {"properties": [("scalar", 1.0 / 0.9)]}),
-        *_template_items_context_panel("VIEW3D_PT_greasepencil_draw_context_menu", _params.context_menu_event),
     ])
 
     return keymap