Fix leak

Author: shotamatsuda

src/renderers/common/QuadMesh.js

@@ -33,9 +33,6 @@ class QuadGeometry extends BufferGeometry {
 
 }
 
-const _geometry = /*@__PURE__*/ new QuadGeometry();
-
-
 /**
  * This module is a helper for passes which need to render a full
  * screen effect which is quite common in context of post processing.
@@ -56,7 +53,7 @@ class QuadMesh extends Mesh {
 	 */
 	constructor( material = null ) {
 
-		super( _geometry, material );
+		super( new QuadGeometry(), material );
 
 		/**
 		 * The camera to render the quad mesh with.