Bump nltk from 3.5 to 3.6.6 (#1)

Bumps [nltk](https://github.com/nltk/nltk) from 3.5 to 3.6.6.
- [Release notes](https://github.com/nltk/nltk/releases)
- [Changelog](https://github.com/nltk/nltk/blob/develop/ChangeLog)
- [Commits](nltk/nltk@3.5...3.6.6)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -6,7 +6,7 @@ pandas==1.4.3
 rouge==1.0.1
 sentence-transformers==2.2.2
 transformers==4.21.1
-nltk==3.8
+nltk==3.6.6
 evaluate==0.4.0
 rouge==1.0.1
 rouge_score==0.1.2