fix clippy lint

helix-view/src/document.rs

@@ -274,7 +274,7 @@ impl Document {
     #[inline]
     /// Corresponding language scope name. Usually `source.<lang>`.
     pub fn language(&self) -> Option<&str> {
-        self.language.as_ref().map(String::as_str)
+        self.language.as_deref()
     }
 
     #[inline]