refactor: remove unused dotenv calls (#2059)

As explained in the Vercel documentation vercel ignores dot files (see
https://github.com/vercel/vercel/discussions/3962#discussioncomment-4277). It
instead loads the env variables defined in the vercel instance. As a
result we can therefore remove dotenv.

api/top-langs.js

@@ -1,4 +1,3 @@
-import * as dotenv from "dotenv";
 import { renderTopLanguages } from "../src/cards/top-languages-card.js";
 import { blacklist } from "../src/common/blacklist.js";
 import {
@@ -11,8 +10,6 @@ import {
 import { fetchTopLanguages } from "../src/fetchers/top-languages-fetcher.js";
 import { isLocaleAvailable } from "../src/translations.js";
 
-dotenv.config();
-
 export default async (req, res) => {
   const {
     username,