build(deps): bump ckeditor5 and @ckeditor/ckeditor5-build-classic

Bumps [ckeditor5](https://github.com/ckeditor/ckeditor5) to 43.1.1 and updates ancestor dependency [@ckeditor/ckeditor5-build-classic](https://github.com/ckeditor/ckeditor5/tree/HEAD/packages/ckeditor5-build-classic). These dependencies need to be updated together.


Updates `ckeditor5` from 40.0.0 to 43.1.1
- [Release notes](https://github.com/ckeditor/ckeditor5/releases)
- [Changelog](https://github.com/ckeditor/ckeditor5/blob/master/CHANGELOG.md)
- [Commits](ckeditor/ckeditor5@v40.0.0...v43.1.1)

Updates `@ckeditor/ckeditor5-build-classic` from 40.0.0 to 43.1.1
- [Release notes](https://github.com/ckeditor/ckeditor5/releases)
- [Changelog](https://github.com/ckeditor/ckeditor5/blob/master/CHANGELOG.md)
- [Commits](https://github.com/ckeditor/ckeditor5/commits/v43.1.1/packages/ckeditor5-build-classic)

---
updated-dependencies:
- dependency-name: ckeditor5
  dependency-type: indirect
- dependency-name: "@ckeditor/ckeditor5-build-classic"
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>