Fix the many_materials and edit_material_on_gltf examples.

Author: andriyDev

examples/3d/edit_material_on_gltf.rs

@@ -75,7 +75,7 @@ fn change_material(
         if let Some(material) = mesh_materials
             .get(descendants)
             .ok()
-            .and_then(|id| asset_materials.get_mut(id.id()))
+            .and_then(|id| asset_materials.get_cloned_mut(id.id()))
         {
             // Create a copy of the material and override base color
             // If you intend on creating multiple models with the same tint, it

examples/stress_tests/many_materials.rs

@@ -91,7 +91,7 @@ fn animate_materials(
     mut materials: ResMut<Assets<StandardMaterial>>,
 ) {
     for (i, material_handle) in material_handles.iter().enumerate() {
-        if let Some(material) = materials.get_mut(material_handle) {
+        if let Some(material) = materials.get_cloned_mut(material_handle) {
             let color = Color::hsl(
                 ((i as f32 * 2.345 + time.elapsed_secs()) * 100.0) % 360.0,
                 1.0,