Bump chromadb from 0.4.20 to 0.4.21

Bumps [chromadb](https://github.com/chroma-core/chroma) from 0.4.20 to 0.4.21.
- [Release notes](https://github.com/chroma-core/chroma/releases)
- [Changelog](https://github.com/chroma-core/chroma/blob/main/RELEASE_PROCESS.md)
- [Commits](chroma-core/chroma@0.4.20...0.4.21)

---
updated-dependencies:
- dependency-name: chromadb
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -2,7 +2,7 @@
 git+https://github.com/gdedrouas/python-mwxml@xml_format_0.11
 git+https://github.com/mediawiki-utilities/python-mwtypes@updates_schema_0.11
 chainlit==0.7.700
-chromadb==0.4.20
+chromadb==0.4.21
 httptools==0.6.1
 langchain==0.0.351
 mwparserfromhell==0.6.5