remove some mut in queries (#3437)

# Objective

- While reading code, found some queries that are `mut` and not used as such

## Solution

- Remove `mut` when possible


Co-authored-by: François <8672791+mockersf@users.noreply.github.com>

crates/bevy_ecs/src/system/query.rs

@@ -211,7 +211,7 @@ use thiserror::Error;
 /// # struct ComponentA;
 /// # #[derive(Component)]
 /// # struct ComponentB;
-/// fn immutable_query_system(mut query: Query<(&ComponentA, &ComponentB)>) {
+/// fn immutable_query_system(query: Query<(&ComponentA, &ComponentB)>) {
 ///     for (a, b) in query.iter() {
 ///         // Here, `a` and `b` are normal references to components, relatively of
 ///         // `&ComponentA` and `&ComponentB` types.

crates/bevy_pbr/src/render/mesh.rs

@@ -584,14 +584,14 @@ pub fn queue_mesh_view_bind_groups(
     light_meta: Res<LightMeta>,
     global_light_meta: Res<GlobalLightMeta>,
     view_uniforms: Res<ViewUniforms>,
-    mut views: Query<(Entity, &ViewShadowBindings, &ViewClusterBindings)>,
+    views: Query<(Entity, &ViewShadowBindings, &ViewClusterBindings)>,
 ) {
     if let (Some(view_binding), Some(light_binding), Some(point_light_binding)) = (
         view_uniforms.uniforms.binding(),
         light_meta.view_gpu_lights.binding(),
         global_light_meta.gpu_point_lights.binding(),
     ) {
-        for (entity, view_shadow_bindings, view_cluster_bindings) in views.iter_mut() {
+        for (entity, view_shadow_bindings, view_cluster_bindings) in views.iter() {
             let view_bind_group = render_device.create_bind_group(&BindGroupDescriptor {
                 entries: &[
                     BindGroupEntry {

crates/bevy_sprite/src/render/mod.rs

@@ -480,7 +480,7 @@ pub fn queue_sprites(
     mut pipeline_cache: ResMut<RenderPipelineCache>,
     mut image_bind_groups: ResMut<ImageBindGroups>,
     gpu_images: Res<RenderAssets<Image>>,
-    mut sprite_batches: Query<(Entity, &SpriteBatch)>,
+    sprite_batches: Query<(Entity, &SpriteBatch)>,
     mut views: Query<&mut RenderPhase<Transparent2d>>,
     events: Res<SpriteAssetEvents>,
 ) {
@@ -514,7 +514,7 @@ pub fn queue_sprites(
             SpritePipelineKey { colored: true },
         );
         for mut transparent_phase in views.iter_mut() {
-            for (entity, batch) in sprite_batches.iter_mut() {
+            for (entity, batch) in sprite_batches.iter() {
                 image_bind_groups
                     .values
                     .entry(batch.handle.clone_weak())

crates/bevy_text/src/text2d.rs

@@ -44,7 +44,7 @@ pub fn extract_text2d_sprite(
     texture_atlases: Res<Assets<TextureAtlas>>,
     text_pipeline: Res<DefaultTextPipeline>,
     windows: Res<Windows>,
-    mut text2d_query: Query<(Entity, &Text, &GlobalTransform, &Text2dSize)>,
+    text2d_query: Query<(Entity, &Text, &GlobalTransform, &Text2dSize)>,
 ) {
     let mut extracted_sprites = render_world.get_resource_mut::<ExtractedSprites>().unwrap();
     let scale_factor = if let Some(window) = windows.get_primary() {
@@ -53,7 +53,7 @@ pub fn extract_text2d_sprite(
         1.
     };
 
-    for (entity, text, transform, calculated_size) in text2d_query.iter_mut() {
+    for (entity, text, transform, calculated_size) in text2d_query.iter() {
         let (width, height) = (calculated_size.size.width, calculated_size.size.height);
 
         if let Some(text_layout) = text_pipeline.get_glyphs(&entity) {

crates/bevy_ui/src/render/mod.rs

@@ -416,7 +416,7 @@ pub fn queue_uinodes(
     mut pipeline_cache: ResMut<RenderPipelineCache>,
     mut image_bind_groups: ResMut<UiImageBindGroups>,
     gpu_images: Res<RenderAssets<Image>>,
-    mut ui_batches: Query<(Entity, &UiBatch)>,
+    ui_batches: Query<(Entity, &UiBatch)>,
     mut views: Query<&mut RenderPhase<TransparentUi>>,
     events: Res<SpriteAssetEvents>,
 ) {
@@ -441,7 +441,7 @@ pub fn queue_uinodes(
         let draw_ui_function = draw_functions.read().get_id::<DrawUi>().unwrap();
         let pipeline = pipelines.specialize(&mut pipeline_cache, &ui_pipeline, UiPipelineKey {});
         for mut transparent_phase in views.iter_mut() {
-            for (entity, batch) in ui_batches.iter_mut() {
+            for (entity, batch) in ui_batches.iter() {
                 image_bind_groups
                     .values
                     .entry(batch.image.clone_weak())