[FIX] mail: correct visual of popover view

Popover view were broken due to change in signature of
component hook `usePosition()` in this PR:
https://github.com/odoo/odoo/pull/85389

Task-2786868

closes odoo/odoo#85954

Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/mail/static/src/components/popover_view/popover_view.js

@@ -17,6 +17,7 @@ export class PopoverView extends Component {
         useComponentToModel({ fieldName: 'component', modelName: 'PopoverView' });
         usePosition(
             () => this.popoverView && this.popoverView.anchorRef && this.popoverView.anchorRef.el,
+            'root',
             {
                 margin: 16,
                 position: this.popoverView.position,