Vertex group weight levels UI/UX improvements

Please improve the UI/UX experience related to weight mapping, particularly with the "Levels" menu option. Currently, when you select a different vertex group while the panel is still showing from a previous operation, the panel does not disappear. It makes it seem that the panel is now there to affect the newly selected vertex group, but it doesn't work that way. My suggestion is to make the Levels panel disappear whenever you select a different vertex group that is no longer associated with the current Levels panel.