Use the correct method to release temporary render textures. Fixes memory leaks from RT's not getting released properly.

Packages/com.unity.postprocessing@3.2.2/PostProcessing/Runtime/PostProcessLayer.cs

@@ -286,7 +286,7 @@ namespace UnityEngine.Rendering.PostProcessing
         {
             if (m_opaqueOnly != null)
             {
-                m_opaqueOnly.Release();
+                RenderTexture.ReleaseTemporary(m_opaqueOnly);
                 m_opaqueOnly = null;
             }
             
@@ -297,7 +297,8 @@ namespace UnityEngine.Rendering.PostProcessing
                 
                 // Blit the upscaled image to the backbuffer
                 Graphics.Blit(m_upscaledOutput, dst);
-                m_upscaledOutput.Release();
+                RenderTexture.ReleaseTemporary(m_upscaledOutput);
+                m_upscaledOutput = null;
                 return;
             }