[6.0/editor] Fixed scene filtering with rendergraph not working on metal

Editor: when doing scene filter we reuse depth from the "normal" render pass to draw selection highlights in "filter" pass, so it needs to be preserved in render graph

Packages/com.unity.render-pipelines.universal/Runtime/UniversalRendererRenderGraph.cs

@@ -622,6 +622,12 @@ void CreateRenderGraphCameraRenderTargets(RenderGraph renderGraph, bool isCamera
                 RenderingUtils.ReAllocateHandleIfNeeded(ref m_RenderGraphCameraDepthHandle, depthDescriptor, FilterMode.Point, TextureWrapMode.Clamp, name: "_CameraDepthAttachment");
 
                 importDepthParams.discardOnLastUse = lastCameraInTheStack;
+            #if UNITY_EDITOR
+                // scene filtering will reuse "camera" depth  from the normal pass for the "filter highlight" effect
+                if (cameraData.isSceneViewCamera && CoreUtils.IsSceneFilteringEnabled())
+                    importDepthParams.discardOnLastUse = false;
+            #endif
+
                 resourceData.cameraDepth = renderGraph.ImportTexture(m_RenderGraphCameraDepthHandle, importDepthParams);
                 resourceData.activeDepthID = UniversalResourceData.ActiveID.Camera;