Keep list menu open after selecting all

Typically when you select all records it's because you want
to operate on those records immediately. The only case
this wouldn't be true is if you were scrolling, then selecting all
a bunch of times. I think it's more likely someone just wants to
select all, then delete.

ListMenu.tsx

@@ -44,7 +44,6 @@ export default function ListMenu({
   }
 
   const select = () => {
-    setShowMenu(false)
     onSelect()
   }