Fix #8183: Allow menu to be presented properly in compact-width iPads

Unfortunately PanModal enforces the presentation to a `popover` on iPads regardless of size classes, so we must allow the arrow direction to be `down` as well here since the toolbar will be at the bottom on compact-width size classes. This also means that on iPads even with iPhone layouts they get shown as a popover which is not ideal and should be fixed later.

Sources/Brave/Frontend/Browser/BrowserViewController/BrowserViewController+ToolbarDelegate.swift

@@ -878,7 +878,7 @@ extension BrowserViewController: ToolbarDelegate {
     presentPanModal(menuController, sourceView: tabToolbar.menuButton, sourceRect: tabToolbar.menuButton.bounds)
     if menuController.modalPresentationStyle == .popover {
       menuController.popoverPresentationController?.popoverLayoutMargins = .init(equalInset: 4)
-      menuController.popoverPresentationController?.permittedArrowDirections = [.up]
+      menuController.popoverPresentationController?.permittedArrowDirections = [.up, .down]
     }
   }