change currentRenderState to renderStack.pop() in WebGLRenderer.compile() (#30607)

Author: cmhhelgeson

src/renderers/WebGLRenderer.js

@@ -1028,8 +1028,7 @@ class WebGLRenderer {
 
 			} );
 
-			renderStateStack.pop();
-			currentRenderState = null;
+			currentRenderState = renderStateStack.pop();
 
 			return materials;