clean up some .gitignores

I'd be tempted to remove even another half of these,
but I'm not really clear on what they are.

Change-Id: Ib18f02d651f32d4437f55e79c2d05b5e34b0b1e1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/213844
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
1 file changed