Cleanup: don't sub-class other registered classes

This complicates registration logic, ideally this would raise an
exception however detecting this at run-time is quite expensive.

scripts/startup/bl_ui/properties_data_mesh.py

@@ -679,7 +679,7 @@ class MESH_UL_color_attributes_selector(UIList, ColorAttributesListBase):
         layout.prop(attribute, "name", text="", icon='GROUP_VCOL')
 
 
-class DATA_PT_vertex_colors(DATA_PT_mesh_attributes, Panel):
+class DATA_PT_vertex_colors(MeshButtonsPanel, Panel):
     bl_label = "Color Attributes"
     bl_options = {'DEFAULT_CLOSED'}
     COMPAT_ENGINES = {