Fix(LLMLingua): support bf16

[iofu728]

What does this PR do?

Fixes bf16

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Was this discussed/approved via a Github issue? Please add a link
  to it if that's the case.
• Did you make sure to update the documentation with your changes?
• Did you write any new necessary tests?

Who can review?

@iofu728

[Copilot]

PR Overview

This PR addresses bf16 support improvements in LLMLingua. Key changes include:

• Updating the copyright header to include 2025.
• Removing a redundant .numpy() call in the prompt compressor, likely to streamline bf16 processing.

Reviewed Changes

File	Description
llmlingua/prompt_compressor.py	Removed the .numpy() conversion in sentence packaging logic to support bf16

Copilot reviewed 1 out of 1 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

llmlingua/prompt_compressor.py:1337

• Removing the .numpy() call assumes that the tensor returned by get_condition_ppl is a single-element tensor. Please verify that this change does not lead to runtime errors when processing bf16 values.

.numpy()