Ignore viewport size/position on iOS (#4922)

I disabled some code that changes the viewport of iOS devices. 
* [X] I have followed the instructions in the PR template

crates/egui-winit/src/lib.rs

@@ -1607,7 +1607,11 @@ pub fn create_winit_window_attributes(
         .with_decorations(decorations.unwrap_or(true))
         .with_resizable(resizable.unwrap_or(true))
         .with_visible(visible.unwrap_or(true))
-        .with_maximized(maximized.unwrap_or(false))
+        .with_maximized(if cfg!(target_os = "ios") {
+            true
+        } else {
+            maximized.unwrap_or(false)
+        })
         .with_window_level(match window_level.unwrap_or_default() {
             egui::viewport::WindowLevel::AlwaysOnBottom => WindowLevel::AlwaysOnBottom,
             egui::viewport::WindowLevel::AlwaysOnTop => WindowLevel::AlwaysOnTop,
@@ -1631,27 +1635,31 @@ pub fn create_winit_window_attributes(
         })
         .with_active(active.unwrap_or(true));
 
+    #[cfg(not(target_os = "ios"))]
     if let Some(size) = inner_size {
         window_attributes = window_attributes.with_inner_size(PhysicalSize::new(
             pixels_per_point * size.x,
             pixels_per_point * size.y,
         ));
     }
 
+    #[cfg(not(target_os = "ios"))]
     if let Some(size) = min_inner_size {
         window_attributes = window_attributes.with_min_inner_size(PhysicalSize::new(
             pixels_per_point * size.x,
             pixels_per_point * size.y,
         ));
     }
 
+    #[cfg(not(target_os = "ios"))]
     if let Some(size) = max_inner_size {
         window_attributes = window_attributes.with_max_inner_size(PhysicalSize::new(
             pixels_per_point * size.x,
             pixels_per_point * size.y,
         ));
     }
 
+    #[cfg(not(target_os = "ios"))]
     if let Some(pos) = position {
         window_attributes = window_attributes.with_position(PhysicalPosition::new(
             pixels_per_point * pos.x,