Remove nonexistent bots from mb_config.pyl

I noticed that I forgot to remove android_unswarmed_n5_rel from mb_config.pyl
in https://chromium-review.googlesource.com/c/chromium/src/+/1135556, so I
tried to write some code to check that all bots referenced in mb_config.pyl
actually exist now that the bot inventory exists src-side.

I couldn't get that to work reliably, but I manually went through the list
my code produced and removed the bots that appear to really not exist according
to cs.chromium.org.

Bug: 863167
Change-Id: I4aa4744d8fda8771eded403a8ebfbfca0f09de12
Reviewed-on: https://chromium-review.googlesource.com/1138338
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576495}
1 file changed