v2.5.3

What's Changed

• change encoding to utf8 by @xiangtianyu in #81
• fix chioces npe by @xiangtianyu in #82
• Chat reference code by @xiangtianyu in #83
• fix rag return bug by @xiangtianyu in #84
• improve class pattern by @xiangtianyu in #85
• Optimizes the file creation logic of the NewFileUtils class by @PerryZhao in #86
• fix test case call wrong method by @xiangtianyu in #88

Full Changelog: v2.5.2...v2.5.3