Don't use the new iPad modal presentation mode for the timeline item menu. (#3325)

ElementX/Sources/Screens/Timeline/View/ItemMenu/TimelineItemMenu.swift

@@ -51,6 +51,7 @@ struct TimelineItemMenu: View {
             }
         }
         .accessibilityIdentifier(A11yIdentifiers.roomScreen.timelineItemActionMenu)
+        .presentationPage()
         .presentationDetents([.medium, .large])
         .presentationBackground(Color.compound.bgCanvasDefault)
         .presentationDragIndicator(.visible)
@@ -233,6 +234,17 @@ private extension EncryptionAuthenticity {
     }
 }
 
+private extension View {
+    /// Uses the old page style modal so that on iPadOS 18 the presentation detents have no effect.
+    @ViewBuilder func presentationPage() -> some View {
+        if #available(iOS 18.0, *) {
+            presentationSizing(.page)
+        } else {
+            self
+        }
+    }
+}
+
 // MARK: - Previews
 
 struct TimelineItemMenu_Previews: PreviewProvider, TestablePreview {