Null pointer exception fix when no directional light in the scene.

ScriptableRenderPipeline/HDRenderPipeline/Lighting/ReflectionProbeCache.cs

                         if (result == null)
                             return -1;
 
-                        m_TextureCache.UpdateSlice(cmd, sliceIndex, m_ConvolutionTargetTexture, m_TextureCache.GetTextureUpdateCount(texture)); // Be careful to provide the update count from the input texture, not the temporary one used for convolving.
+                        m_TextureCache.UpdateSlice(cmd, sliceIndex, result, m_TextureCache.GetTextureUpdateCount(texture)); // Be careful to provide the update count from the input texture, not the temporary one used for convolving.
 
                         m_ProbeBakingState[sliceIndex] = ProbeFilteringState.Ready;
                     }

ScriptableRenderPipeline/HDRenderPipeline/Sky/SkyManager.cs

                 m_BuiltinParameters.screenSize = m_CubemapScreenSize;
                 m_BuiltinParameters.cameraPosWS = camera.camera.transform.position;
 
-                int sunHash = (sunLight.GetHashCode() * 23 + sunLight.transform.position.GetHashCode()) * 23 + sunLight.transform.rotation.GetHashCode();
+                int sunHash = 0;
+                if(sunLight != null)
+                    sunHash = (sunLight.GetHashCode() * 23 + sunLight.transform.position.GetHashCode()) * 23 + sunLight.transform.rotation.GetHashCode();
                 int skyHash = sunHash * 23 + skySettings.GetHashCode();
 
                 if (m_UpdatedFramesRequired > 0 ||