Delete deprecated SkLightingImageFilter header

Bug: skia:11230
Change-Id: I8983d160ff0317514572d13aa2a3f1218e15da8e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/371959
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
6 files changed