fix(cli-repl): drop nanobus in production usage MONGOSH-1330 (#1366)

nanobus inherently leaks memory, which means that it can
make mongosh crash in certain scenarios.

Since we do not actually use the features of nanobus
(mostly being able to listen for a generic `'*'` event),
just replace it with the standard `EventEmitter` to fix this.

packages/cli-repl/package.json

@@ -74,7 +74,6 @@
     "js-yaml": "^4.1.0",
     "mongodb-connection-string-url": "^2.5.3",
     "mongodb-log-writer": "^1.1.3",
-    "nanobus": "^4.4.0",
     "numeral": "^2.0.6",
     "pretty-repl": "^3.1.1",
     "semver": "^7.1.2",

packages/cli-repl/src/cli-repl.ts

@@ -9,9 +9,9 @@ import { Editor } from '@mongosh/editor';
 import { redactSensitiveData } from '@mongosh/history';
 import Analytics from 'analytics-node';
 import askpassword from 'askpassword';
+import { EventEmitter } from 'events';
 import yaml from 'js-yaml';
 import ConnectionString from 'mongodb-connection-string-url';
-import Nanobus from 'nanobus';
 import semver from 'semver';
 import { Readable, Writable } from 'stream';
 import { buildInfo } from './build-info';
@@ -104,7 +104,7 @@ class CliRepl implements MongoshIOProvider {
    * Instantiate the new CLI Repl.
    */
   constructor(options: CliReplOptions) {
-    this.bus = new Nanobus('mongosh');
+    this.bus = new EventEmitter();
     this.cliOptions = options.shellCliOptions;
     this.input = options.input;
     this.output = options.output;