EEVEE Next: Ensure HiZ buffer update flag is cleared

HiZ dirty flag was previously not cleared upon update
resulting in duplicate updates in several places, without
source depth input having changed.

Authored by Apple: Michael Parkin-White

Co-authored-by: Michael Parkin-White <mparkinwhite@apple.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/115235

source/blender/draw/engines/eevee_next/eevee_hizbuffer.cc

@@ -95,6 +95,8 @@ void HiZBuffer::update()
   else {
     inst_.manager->submit(hiz_update_layer_ps_);
   }
+
+  is_dirty_ = false;
 }
 
 void HiZBuffer::debug_draw(View &view, GPUFrameBuffer *view_fb)