Fix TreeView so that the row height always matches the chevron height (#6950)

Author: LFDanLu

packages/@react-spectrum/tree/src/TreeView.tsx

@@ -140,8 +140,7 @@ const treeCellGrid = style({
   display: 'grid',
   width: 'full',
   alignItems: 'center',
-  // TODO: needed to use spectrum var since gridTemplateColumns uses baseSizing and not scaled sizing
-  gridTemplateColumns: ['minmax(0, auto)', 'minmax(0, auto)', 'minmax(0, auto)', 'var(--spectrum-global-dimension-size-500)', 'minmax(0, auto)', '1fr', 'minmax(0, auto)', 'auto'],
+  gridTemplateColumns: ['minmax(0, auto)', 'minmax(0, auto)', 'minmax(0, auto)', 'minmax(0, auto)', 'minmax(0, auto)', '1fr', 'minmax(0, auto)', 'auto'],
   gridTemplateRows: '1fr',
   gridTemplateAreas: [
     'drag-handle checkbox level-padding expand-button icon content actions actionmenu'