fix: update Octokit.plugin() API to remove deprecation

fixes #1654

src/index.ts

@@ -5,16 +5,11 @@ import { restEndpointMethods } from "@octokit/plugin-rest-endpoint-methods";
 
 import { VERSION } from "./version";
 
-export const Octokit = Core.plugin([
-  // Workaround to prevent TypeScript from widening the inferred return type of
-  // plugins passed to Octokit, which would result in type information (e.g.
-  // methods provided by plugins) not being added to Octokit instances.
-  //
-  // See https://github.com/octokit/core.js/issues/51#issuecomment-596846088
-  (requestLog as unknown) as () => void,
+export const Octokit = Core.plugin(
+  requestLog,
   restEndpointMethods,
   paginateRest
-]).defaults({
+).defaults({
   userAgent: `octokit-rest.js/${VERSION}`
 });