Incorporate OIT into MeshPipelineKey used by the LineGizmoPipeline (#17946)

Fixes #17945

Check if the view being extracted has OIT enabled and incorporate the
associated bit into the mesh pipeline key.

I basically have no idea what's going on in the renderer, so let me know
if I missed something, which is extraordinarily possible.

I modified the `order_independent_transparency` example to put
everything on the default render layer and render a gizmo at the origin.
Previously, this would cause the application to panic.

Author: mweatherley

crates/bevy_gizmos/src/pipeline_3d.rs

@@ -7,6 +7,7 @@ use crate::{
 use bevy_app::{App, Plugin};
 use bevy_core_pipeline::{
     core_3d::{Transparent3d, CORE_3D_DEPTH_FORMAT},
+    oit::OrderIndependentTransparencySettings,
     prepass::{DeferredPrepass, DepthPrepass, MotionVectorPrepass, NormalPrepass},
 };
 
@@ -294,6 +295,7 @@ fn queue_line_gizmos_3d(
             Has<DepthPrepass>,
             Has<MotionVectorPrepass>,
             Has<DeferredPrepass>,
+            Has<OrderIndependentTransparencySettings>,
         ),
     )>,
 ) {
@@ -304,7 +306,7 @@ fn queue_line_gizmos_3d(
         view,
         msaa,
         render_layers,
-        (normal_prepass, depth_prepass, motion_vector_prepass, deferred_prepass),
+        (normal_prepass, depth_prepass, motion_vector_prepass, deferred_prepass, oit),
     ) in &mut views
     {
         let Some(transparent_phase) = transparent_render_phases.get_mut(&view_entity) else {
@@ -332,6 +334,10 @@ fn queue_line_gizmos_3d(
             view_key |= MeshPipelineKey::DEFERRED_PREPASS;
         }
 
+        if oit {
+            view_key |= MeshPipelineKey::OIT_ENABLED;
+        }
+
         for (entity, main_entity, config) in &line_gizmos {
             if !config.render_layers.intersects(render_layers) {
                 continue;