fix: align function tool module path with plugin main module (#7462)

Author: railgun19457

astrbot/core/star/context.py

@@ -494,7 +494,7 @@ def add_llm_tools(self, *tools: FunctionTool) -> None:
                     _parts.append(part)
                     if part in flags and i + 1 < len(module_part):
                         _parts.append(module_part[i + 1])
-                        module_part.append("main")
+                        _parts.append("main")
                         break
                 tool.handler_module_path = ".".join(_parts)
                 module_path = tool.handler_module_path