GC fix (24B)

ScriptableRenderPipeline/HDRenderPipeline/Sky/HDRISky/HDRISkyRenderer.cs

     public class HDRISkyRenderer : SkyRenderer
     {
         Material m_SkyHDRIMaterial; // Renders a cubemap into a render texture (can be cube or 2D)
-        private HDRISkySettings m_HdriSkyParams;
+        MaterialPropertyBlock m_PropertyBlock;
+        HDRISkySettings m_HdriSkyParams;
+            m_PropertyBlock = new MaterialPropertyBlock();
         }
 
         public override void Build()
             m_SkyHDRIMaterial.SetVector(HDShaderIDs._SkyParam, new Vector4(m_HdriSkyParams.exposure, m_HdriSkyParams.multiplier, m_HdriSkyParams.rotation, 0.0f));
 
             // This matrix needs to be updated at the draw call frequency.
-            MaterialPropertyBlock properties = new MaterialPropertyBlock();
-            properties.SetMatrix(HDShaderIDs._PixelCoordToViewDirWS, builtinParams.pixelCoordToViewDirMatrix);
+            m_PropertyBlock.SetMatrix(HDShaderIDs._PixelCoordToViewDirWS, builtinParams.pixelCoordToViewDirMatrix);
-            CoreUtils.DrawFullScreen(builtinParams.commandBuffer, m_SkyHDRIMaterial, properties, renderForCubemap ? 0 : 1);
+            CoreUtils.DrawFullScreen(builtinParams.commandBuffer, m_SkyHDRIMaterial, m_PropertyBlock, renderForCubemap ? 0 : 1);
         }
 
         public override bool IsSkyValid()