Due to (optimization) checks in in `BKE_gpencil_prepare_eval_data` & `BKE_gpencil_update_layer_transforms`, updates were skipped if animation reached exact identity transforms. Now check if the matrix has changed additionally to gain proper updates. Unsure if this is the cheapest way to check for the animated state of layer transforms tbh, but I see similar checks elsewhere. Fixes T101164. Maniphest Tasks: T101164 Differential Revision: https://developer.blender.org/D16018