[autoroll] Remove the 'warning' emails for the chromite-chromium roller.
[autoroll] Remove the 'warning' emails for the chromite-chromium roller.

It can be a bit spammy when the chromium CQ flakes.

Fortunately the auto bug-filing mechanism works well, and covers any
scenario where manual intervention is needed.

Bug: none
Change-Id: I9ff6a2b8f9687d29cc323f79768ee42a08894ed8
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/246001
Reviewed-by: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@google.com>
Reviewed-by: Achuith Bhandarkar <885eb1ed0dfe5e52160a872becbca30c7fb85e73@google.com>
Reviewed-by: Achuith Bhandarkar <885eb1ed0dfe5e52160a872becbca30c7fb85e73@chromium.org>
Commit-Queue: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@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