Remove sa-keys-checker alerts from Thanos.
Remove sa-keys-checker alerts from Thanos.

Bug: skia:13542
Change-Id: I13cff3d406c4e4eb051048cab3a0d7244683f3d6
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/565180
Reviewed-by: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@google.com>
Auto-Submit: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>
Commit-Queue: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>
Commit-Queue: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot