refactor: remove new_simple methods and replace with new(None, None)

Co-authored-by: aider (openai/andrew/openrouter/deepseek/deepseek-chat-v3.1) <aider@aider.chat>

src/meta_plugin/user.rs

@@ -25,9 +25,6 @@ impl UserMetaPlugin {
         }
     }
     
-    pub fn new_simple() -> UserMetaPlugin {
-        Self::new(None, None)
-    }
     
     fn get_current_username() -> Option<String> {
         uzers::get_user_by_uid(uzers::get_current_uid())