Remove invalid comments

[ChristopherRemde]

In PointcloudRenderRT.cs, there are comments still erroniously refering to the Polyspatial pipeline:

Geometry_Sequence_Player_Package/Runtime/Scripts/Rendering/PointcloudRendererRT.cs

Line 118 in 93b6d62

/// <summary>

Geometry_Sequence_Player_Package/Runtime/Scripts/Rendering/PointcloudRendererRT.cs

Line 320 in 93b6d62

UnityEngine.Debug.LogError("Pointcloud Quads material (Polyspatial) could not be loaded!");

We should remove/change these comments