Add Salesforce xLAM-2 series of model handlers and update vLLM version from 0.6.3 to 0.6.5

[zuxin666]

This PR adds support for the Salesforce xLAM-2 series of models and updates the vLLM dependency from 0.6.3 to 0.6.5 to address a long context issue with Qwen models (referenced in vllm-project/vllm#9769).

Changes

• Added new Salesforce xLAM-2 model handlers:

  • SalesforceLlamaHandler for Llama-based models (xLAM-2-70b-fc-r, xLAM-2-8b-fc-r)
  • SalesforceQwenHandler for Qwen-based models (xLAM-2-32b-fc-r, xLAM-2-3b-fc-r, xLAM-2-1b-fc-r)

• Updated model metadata and supported models documentation to include the new xLAM-2 models

• Bumped vLLM version from 0.6.3 to 0.6.5 in pyproject.toml to fix Qwen's long context issue

Testing

The implementation has been tested with the supported xLAM-2 models to ensure proper function calling capabilities and compatibility with the Berkeley Function Call Leaderboard evaluation framework.

[HuanzhiMao]

Thank you for the PR @zuxin666 ! Excited to see the new xLAM models on the leaderboard 💯💯💯