Remove duplicated header file from sources

It is on skia_sksl_gpu_sources list already.

Bug: skia:10650
Change-Id: I1e4bb0b2346ad8a74ddbdb3d3ff44ea7de6c0cd3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/312736
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
1 file changed