`scene_viewer` example prints warnings after toggling shadow on and off

[akimakinai]

Bevy version

main

This does not reproduce with v0.14.2.

What you did

• Run scene_viewer example and toggle shadow on and off (press U)

What went wrong

No visual problem, but this warning appears repeatedly in terminal:
WARN bevy_pbr::render::gpu_preprocess: The preprocessing index buffer wasn't present

Additional information

bevy/crates/bevy_pbr/src/render/light.rs

Lines 1198 to 1206 in 82d6f56

	if !view_layers.intersects(&light.render_layers) {
	gpu_light.skip = 1u32;
	continue;
	}
	// Only deal with cascades when shadows are enabled.
	if (gpu_light.flags & DirectionalLightFlags::SHADOWS_ENABLED.bits()) == 0u32 {
	continue;
	}

Hitting these conditions cause living (due to now retained render world) entitiy to be removed from live_shadow_mapping_lights in this function, hence removed from ViewBinnedRenderPhases, and later disagrees with query result in GpuPreprocessNode::run.