Global: Remove legacy code. (#30821)

src/materials/Material.js

@@ -997,12 +997,6 @@ class Material extends EventDispatcher {
 
 	}
 
-	onBuild( /* shaderobject, renderer */ ) {
-
-		console.warn( 'Material: onBuild() has been removed.' ); // @deprecated, r166
-
-	}
-
 }
 
 export { Material };