Bump nltk from 3.8.1 to 3.9

Bumps [nltk](https://github.com/nltk/nltk) from 3.8.1 to 3.9.
- [Changelog](https://github.com/nltk/nltk/blob/develop/ChangeLog)
- [Commits](nltk/nltk@3.8.1...3.9)

---
updated-dependencies:
- dependency-name: nltk
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements-lock.txt

@@ -60,7 +60,7 @@ markdown-it-py==3.0.0
 MarkupSafe==2.1.5
 mdurl==0.1.2
 multidict==6.0.5
-nltk==3.8.1
+nltk==3.9
 openai==1.35.3
 opentelemetry-api==1.25.0
 opentelemetry-exporter-otlp-proto-common==1.25.0