fixed the issue that was causing the UI to not render in scene view.

ScriptableRenderPipeline/LightweightPipeline/LightweightPipeline.cs

 
                 cullingParameters.shadowDistance = Mathf.Min(m_ShadowSettings.maxShadowDistance,
                     m_CurrCamera.farClipPlane);
+
+                // emit scene view UI
+                if (camera.cameraType == CameraType.SceneView)
+                    ScriptableRenderContext.EmitWorldGeometryForSceneView(camera);
+
                 CullResults.Cull(ref cullingParameters, context, ref m_CullResults);
 
                 VisibleLight[] visibleLights = m_CullResults.visibleLights.ToArray();