Update node.d.ts (#10418)

It misses "finished" property, please refer official site: https://nodejs.org/api/http.html#http_response_finished

node/node.d.ts

@@ -607,6 +607,7 @@ declare module "http" {
         removeHeader(name: string): void;
         write(chunk: any, encoding?: string): any;
         addTrailers(headers: any): void;
+        finished: boolean;
 
         // Extended base methods
         end(): void;