[Feature] Add qwen2.5 chat templates

[xruifan]

Add chat template support for qwen2.5 base language models and instruction tuned models ranging from 0.5 to 72 billion parameters.

[Harsha-Nori]

Hey @xruifan, really appreciate this! Qwen models are incredible, and it'll be great to support them in guidance. LGTM :).

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

Attention: Patch coverage is 66.66667% with 4 lines in your changes missing coverage. Please review.

Project coverage is 64.03%. Comparing base (da80081) to head (718247e).
Report is 10 commits behind head on main.

Files with missing lines	Patch %	Lines
guidance/chat.py	66.66%	4 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1066      +/-   ##
==========================================
- Coverage   65.40%   64.03%   -1.37%     
==========================================
  Files          63       63              
  Lines        4810     4822      +12     
==========================================
- Hits         3146     3088      -58     
- Misses       1664     1734      +70     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.