(retriever) use vLLM for nemotron-parse inference

[edknv]

Description

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.
• If adjusting docker-compose.yaml environment variables have you ensured those are mimicked in the Helm values.yaml file.

[jperez999]

Let me know if those comments make sense. Otherwise looks good.