Patch release v5.12.1

# Patch release v5.12.1 Updated the lower bound for PEFT and a fix for auto tokenizer to properly resolve the mistral tokenizer (when `mistral-common` is installed). This is similar to v.5.10.3 minus the fixes that were already included in the main release - vLLM will first target 5.10.3 :hugs: * Fix `peft` lower bound #46605 by @hmellor (#46605) * mistral common backend fix #46667 by @itazap (#46667) **Full Changelog**: https://github.com/huggingface/transformers/compare/v5.12.0...v5.12.1