Fix query_gltf_primitives example (bevyengine#15715)

This example was missed during the port to required components for
meshes and materials.
Easy fix, I checked that it works as it did in the PR that added the
example (bevyengine#13912).

examples/3d/query_gltf_primitives.rs

@@ -23,7 +23,11 @@ fn find_top_material_and_mesh(
  mut materials: ResMut<Assets<StandardMaterial>>,
  mut meshes: ResMut<Assets<Mesh>>,
  time: Res<Time>,
- mat_query: Query<(&Handle<StandardMaterial>, &Handle<Mesh>, &GltfMaterialName)>,
+ mat_query: Query<(
+ &MeshMaterial3d<StandardMaterial>,
+ &Mesh3d,
+ &GltfMaterialName,
+ )>,
 ) {
  for (mat_handle, mesh_handle, name) in mat_query.iter() {
  // locate a material by material name