Update doc/contributing/large-pull-requests.md

Co-authored-by: Joyee Cheung <joyeec9h3@gmail.com>

Author: mcollina

doc/contributing/large-pull-requests.md

@@ -45,7 +45,7 @@ even if they exceed the line threshold:
 * Web Platform Tests (WPT) imports and updates.
 * Other bot-issued or automated pull requests (e.g., license updates, test
   fixture regeneration).
-
+* Test-only refactoring that involves no functional changes.
 These pull requests already have established review processes and do not
 benefit from the additional requirements described here.