Remove deprecated abab package (#183383)

## Summary

This PR removes deprecated [`abab`](https://www.npmjs.com/package/abab)
package.

### For maintainers

- [ ] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

Co-authored-by: Jeramy Soucy <jeramy.soucy@elastic.co>

package.json

@@ -1552,7 +1552,6 @@
     "@typescript-eslint/typescript-estree": "^5.62.0",
     "@wojtekmaj/enzyme-adapter-react-17": "^0.6.7",
     "@yarnpkg/lockfile": "^1.1.0",
-    "abab": "^2.0.4",
     "aggregate-error": "^3.1.0",
     "apidoc-markdown": "^7.3.0",
     "argsplit": "^1.0.5",

x-pack/dev-tools/api_debug/request_from_api.js

@@ -7,7 +7,6 @@
 
 import fetch from 'node-fetch';
 import { resolve } from 'path';
-import abab from 'abab';
 import pkg from '../../package.json';
 import { X_ELASTIC_INTERNAL_ORIGIN_REQUEST } from '@kbn/core-http-common/src/constants';
 
@@ -17,7 +16,7 @@ function getRequestParams(argv) {
   // use `--auth=myuser:mypassword` or else elastic:changeme is defaulted
   // passing `--auth` with no value effectively sends no auth
   const auth = argv.auth || 'elastic:changeme';
-  const authStr = abab.btoa(auth);
+  const authStr = Buffer.from(auth).toString('base64');
   // auto-add a leading slash to basePath
   const basePath = argv.basePath ? '/' + argv.basePath : '';
 

x-pack/test/functional_cors/plugins/kibana_cors_test/server/plugin.ts

@@ -8,12 +8,11 @@
 import Hapi from '@hapi/hapi';
 import { kbnTestConfig } from '@kbn/test/kbn_test_config';
 import Url from 'url';
-import abab from 'abab';
 
 import type { Plugin, CoreSetup, CoreStart, PluginInitializerContext } from '@kbn/core/server';
 import type { ConfigSchema } from './config';
 
-const apiToken = abab.btoa(kbnTestConfig.getUrlParts().auth!);
+const apiToken = Buffer.from(kbnTestConfig.getUrlParts().auth!).toString('base64');
 
 function renderBody(kibanaUrl: string) {
   const url = Url.resolve(kibanaUrl, '/cors-test');

yarn.lock

@@ -11383,7 +11383,7 @@
   resolved "https://registry.yarnpkg.com/@yarnpkg/lockfile/-/lockfile-1.1.0.tgz#e77a97fbd345b76d83245edcd17d393b1b41fb31"
   integrity sha512-GpSwvyXOcOOlV70vbnzjj4fW5xW/FdUF6nQEt1ENy7m4ZCczi1+/buVUPAqmGfqznsORNFzUMjctTIp8a9tuCQ==
 
-abab@^2.0.4, abab@^2.0.6:
+abab@^2.0.6:
   version "2.0.6"
   resolved "https://registry.yarnpkg.com/abab/-/abab-2.0.6.tgz#41b80f2c871d19686216b82309231cfd3cb3d291"
   integrity sha512-j2afSsaIENvHZN2B8GOpF566vZ5WVk5opAiMTvWgaQT8DkbOqsTfvNAvHoRGU2zzP8cPoqys+xHTRDWW8L+/BA==