[gtk/drop-gl] tests: Remove an outdated comment

[Matthias Clasen <matthiasc src gnome org>]

commit ea31ae31c13ffd17f2bcde2d006b55e5bc02ef1d
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Aug 22 12:29:59 2021 -0400

    tests: Remove an outdated comment
    
    It refers to a file that no longer exists.

 testsuite/gsk/transform.c | 2 --
 1 file changed, 2 deletions(-)
---
diff --git a/testsuite/gsk/transform.c b/testsuite/gsk/transform.c
index b87699d5c7..273f5d546a 100644
--- a/testsuite/gsk/transform.c
+++ b/testsuite/gsk/transform.c
@@ -443,8 +443,6 @@ gsk_matrix_transform_rect (const graphene_matrix_t *m,
  * determine if transforming an axis-aligned rectangle produces
  * axis-aligned output, to decide whether to use linear
  * interpolation or not.
- *
- * Keep this in sync with gsk/gl/gskglrenderer.c
  */
 static gboolean
 result_is_axis_aligned (GskTransform          *transform,