Test that WebGLRenderingContext exists (#26306)

It is not a case in node.js - making impossible to use WebGLRenderer
there.

src/renderers/WebGLRenderer.js

@@ -289,7 +289,7 @@ class WebGLRenderer {
 
 			}
 
-			if ( _gl instanceof WebGLRenderingContext ) { // @deprecated, r153
+			if ( typeof WebGLRenderingContext !== 'undefined' && _gl instanceof WebGLRenderingContext ) { // @deprecated, r153
 
 				console.warn( 'THREE.WebGLRenderer: WebGL 1 support was deprecated in r153 and will be removed in r163.' );