remove unused vllm library (Worker)

[jacklanchantin]

What does this PR do? Please describe: A summary of the change or the issue that is fixed.

Removes unused vllm function import (Worker) which was removed in v0.11.0

Does your PR introduce any breaking changes? If yes, please list them: List of all backwards-incompatible changes.

Check list:

• [ ] Was the content of this PR discussed and approved via a GitHub issue? (no need for typos or documentation improvements)
• [ ] Did you read the contributor guideline?
• [ ] Did you make sure that your PR does only one thing instead of bundling different changes together?
• [ ] Did you make sure to update the documentation with your changes? (if necessary)
• [ ] Did you write any new necessary tests?
• [ ] Did you verify new and existing tests pass locally with your changes?
• [ ] Did you update the CHANGELOG? (no need for typos, documentation, or minor internal changes)