Remove dispose() of now removed depthMaterial (#26946)

Fixes Uncaught TypeError: Cannot read properties of undefined (reading 'dispose')

examples/jsm/postprocessing/SAOPass.js

@@ -314,7 +314,6 @@ class SAOPass extends Pass {
 		this.blurIntermediateRenderTarget.dispose();
 		this.normalRenderTarget.dispose();
 
-		this.depthMaterial.dispose();
 		this.normalMaterial.dispose();
 		this.saoMaterial.dispose();
 		this.vBlurMaterial.dispose();