feat(dev-infra): add a command to verify NgBot YAML config syntax (#39071)

This commit adds a new command to the `ng-dev` suite, which verifies that the NgBot YAML config is
correct. It also adds this command to the `lint` CircleCI job so that we execute this check while
running CI.

This should help prevent syntax errors similar to the one introduced in:
393ce5574b

PR Close #39071

dev-infra/ngbot/cli.ts

@@ -0,0 +1,19 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import * as yargs from 'yargs';
+import {verify} from './verify';
+
+/** Build the parser for the NgBot commands. */
+export function buildNgbotParser(localYargs: yargs.Argv) {
+  return localYargs.help().strict().demandCommand().command(
+      'verify', 'Verify the NgBot config', {}, () => verify());
+}
+
+if (require.main === module) {
+  buildNgbotParser(yargs).parse();
+}