fix: mitigate DangerJS transpilation bug (#47192)

Summary:
Danger seems to have a bug where it's not transpiling the import of
rnx-kit/rn-changelog-generator. This mitigates the issue to get our
project back on track.

This can be replicated locally by:

```bash
DEBUG="*" DANGER_GITHUB_API_TOKEN=$GITHUB_TOKEN yarn danger pr #47182
```
You can see it running correctly here when switching to the branch with the fix.  **I'm a little concerned that this is still failing on the PR**.  Thoughts?

 {F1946190275}

Changelog: [internal]

Pull Request resolved: #47192

Reviewed By: cortinico

Differential Revision: D64924466

Pulled By: blakef

fbshipit-source-id: 68df0521620809effe3a78ce842e043382ad64a6

Author: blakef

packages/react-native-bots/dangerfile.js

@@ -8,9 +8,6 @@
  */
 
 'use strict';
-
-const {validate: validateChangelog} =
-  require('@rnx-kit/rn-changelog-generator').default;
 const {danger, fail, /*message,*/ warn} = require('danger');
 const includes = require('lodash.includes');
 
@@ -60,7 +57,9 @@ if (!includesTestPlan && !isFromPhabricator) {
 
 // Check if there is a changelog and validate it
 if (!isFromPhabricator) {
-  const status = validateChangelog(danger.github.pr.body);
+  const status = require('@rnx-kit/rn-changelog-generator').default.validate(
+    danger.github.pr.body,
+  );
   const changelogInstructions =
     'See <a target="_blank" href="https://reactnative.dev/contributing/changelogs-in-pull-requests">Changelog format</a>';
   if (status === 'missing') {