Match get_sub_app_mut as an Option

Addresses Bevy [9202](bevyengine/bevy#9202)

Author: zhaop

crates/transform-gizmo-bevy/src/render.rs

@@ -46,7 +46,7 @@ impl Plugin for TransformGizmoRenderPlugin {
         app.init_resource::<DrawDataHandles>()
             .add_plugins(RenderAssetPlugin::<GizmoDrawData>::default());
 
-        let Ok(render_app) = app.get_sub_app_mut(RenderApp) else {
+        let Some(render_app) = app.get_sub_app_mut(RenderApp) else {
             return;
         };
 
@@ -62,7 +62,7 @@ impl Plugin for TransformGizmoRenderPlugin {
     }
 
     fn finish(&self, app: &mut App) {
-        let Ok(render_app) = app.get_sub_app_mut(RenderApp) else {
+        let Some(render_app) = app.get_sub_app_mut(RenderApp) else {
             return;
         };