delete: 移除不再使用的配置文件和开发依赖，清理代码库

src/neobot/plugins/__init__.py

@@ -5,7 +5,6 @@ NEO Bot Plugins Package
 """
 
 from . import admin
-from . import ai_chat
 from . import auto_approve
 from . import bot_status
 from . import broadcast
@@ -23,7 +22,6 @@ from . import weather
 
 __all__ = [
     "admin",
-    "ai_chat",
     "auto_approve",
     "bot_status",
     "broadcast",