GitLab

The scheduled beta trigger and the poller stable trigger do not trigger
any jobs. This can't be generated natively by lucicfg, so remove the
triggers. stable-gitiles-trigger-scheduled was renamed to
stable-gitiles-trigger to match what will be generated by starlark.

Bug: 1011908
Change-Id: I9827d933c8b92c78ab4a44a3ca4b2a883b00875a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2031185Reviewed-by: Aaron Gable <agable@chromium.org>
Commit-Queue: Garrett Beaty <gbeaty@chromium.org>
Cr-Commit-Position: refs/heads/master@{#736934}