Remove comments on accessibility configuration

Removed comments explaining the accessibility setup for the
overlay Grid and PopupBorder. No functional changes were
made to the accessibility behavior, as the relevant
`AutomationProperties.SetIsInAccessibleTree` calls remain
unchanged. The comments were likely removed for clarity or
to reduce redundancy.

Author: IeuanWalker

src/CommunityToolkit.Maui/Views/Popup/PopupPage.shared.cs

@@ -251,10 +251,6 @@ public PopupPageLayout(in Popup popupContent, in IPopupOptions options)
 
 			Children.Add(PopupBorder);
 
-			// Configure accessibility: 
-			// - Exclude the overlay Grid from accessibility to hide the background dimming area
-			// - Exclude the PopupBorder from accessibility (it's just a visual container)
-			// - Popup and its inner content children will be accessible directly
 			AutomationProperties.SetIsInAccessibleTree(this, false);
 			AutomationProperties.SetIsInAccessibleTree(PopupBorder, false);
 		}