chore(deps): bump tiktoken from 0.11.0 to 0.12.0

Bumps [tiktoken](https://github.com/openai/tiktoken) from 0.11.0 to 0.12.0.
- [Release notes](https://github.com/openai/tiktoken/releases)
- [Changelog](https://github.com/openai/tiktoken/blob/main/CHANGELOG.md)
- [Commits](openai/tiktoken@0.11.0...0.12.0)

---
updated-dependencies:
- dependency-name: tiktoken
  dependency-version: 0.12.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements/base.txt

@@ -19,4 +19,4 @@ pydantic_core
 python-decouple==3.8
 python-dotenv==1.2.1
 pypdf==6.1.3
-tiktoken==0.11.0
+tiktoken==0.12.0