build(deps-dev): bump nltk in /solutions/enterprise-ai-agent

Bumps [nltk](https://github.com/nltk/nltk) from 3.9.2 to 3.9.3.
- [Changelog](https://github.com/nltk/nltk/blob/develop/ChangeLog)
- [Commits](nltk/nltk@3.9.2...3.9.3)

---
updated-dependencies:
- dependency-name: nltk
  dependency-version: 3.9.3
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]