Bump tiktoken from 0.4.0 to 0.5.1 (#21)

Bumps [tiktoken](https://github.com/openai/tiktoken) from 0.4.0 to 0.5.1.
- [Release notes](https://github.com/openai/tiktoken/releases)
- [Changelog](https://github.com/openai/tiktoken/blob/main/CHANGELOG.md)
- [Commits](openai/tiktoken@0.4.0...0.5.1)

---
updated-dependencies:
- dependency-name: tiktoken
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements.txt

@@ -7,7 +7,7 @@ presidio-anonymizer==2.2.33
 sentence-transformers==2.2.2
 spacy==3.6.1
 tensorflow==2.13.0
-tiktoken==0.4.0
+tiktoken==0.5.1
 torch==2.0.1
 transformers==4.30.2
 xformers==0.0.21