No functional changes expected. The function `BKE_action_get_item_transform_flags` was only ever used in a single place. As such it could be a static function within the given file. This reduction in scope will help with future refactors. This is in service of fixing #126125 since the function in its current form does not support layered actions. Pull Request: https://projects.blender.org/blender/blender/pulls/126287