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.

src/fetchers/stats-fetcher.js

@@ -1,6 +1,5 @@
 // @ts-check
 import axios from "axios";
-import * as dotenv from "dotenv";
 import githubUsernameRegex from "github-username-regex";
 import { calculateRank } from "../calculateRank.js";
 import { retryer } from "../common/retryer.js";
@@ -12,8 +11,6 @@ import {
   wrapTextMultiline,
 } from "../common/utils.js";
 
-dotenv.config();
-
 /**
  * Stats fetcher object.
  *

src/fetchers/top-languages-fetcher.js

@@ -1,5 +1,4 @@
 // @ts-check
-import * as dotenv from "dotenv";
 import { retryer } from "../common/retryer.js";
 import {
   CustomError,
@@ -9,8 +8,6 @@ import {
   wrapTextMultiline,
 } from "../common/utils.js";
 
-dotenv.config();
-
 /**
  * Top languages fetcher object.
  *