Bump llama-index from 0.12.23 to 0.12.28 in /scripts/translate

Bumps [llama-index](https://github.com/run-llama/llama_index) from 0.12.23 to 0.12.28.
- [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@v0.12.23...v0.12.28)

---
updated-dependencies:
- dependency-name: llama-index
  dependency-version: 0.12.28
  dependency-type: direct:production
...

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

Author: dependabot[bot]

scripts/translate/requirements.txt

@@ -15,6 +15,6 @@ sniffio==1.3.1
 tqdm==4.67.1
 typing_extensions==4.12.2
 xxhash==3.5.0
-llama_index==0.12.23
+llama_index==0.12.28
 python-frontmatter
 markdown-it-py