You can scale your
$CollisionShape2D.scale.x = 1.25 # 25% longer
Note that you can't scale Circle or Capsule shapes so you gotta use a Rectangle shape. You will probably need to position the shape, too.
What I would do is to save the
position of the
CollisionShape2D in an
AnimationPlayer with animation length of
0.1, optionally blend between them, then call them like this: