chore(deps): Bump llama-index in /examples/langchain-chroma

Bumps [llama-index](https://github.com/run-llama/llama_index) from 0.11.17 to 0.11.19.
- [Release notes](https://github.com/run-llama/llama_index/releases)
- [Changelog](https://github.com/run-llama/llama_index/blob/main/CHANGELOG.md)
- [Commits](run-llama/llama_index@v0.11.17...v0.11.19)

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

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

Author: dependabot[bot]

examples/langchain-chroma/requirements.txt

@@ -1,4 +1,4 @@
 langchain==0.3.3
 openai==1.51.2
 chromadb==0.5.13
-llama-index==0.11.17
+llama-index==0.11.19