Remove UpdateMetaConfig bot

It's perma-failing, and it doesn't work with Kitchen due to the new
service account not being authorized.  Rather than spend the energy to
fix the service account (and move to an internal repo) I'll just delete
it since it's blocked on a low priority bug with an unknown ETA.

Bug: skia:
Change-Id: I04636fda334f8a878bde2612b3edad65d81986dc
Reviewed-on: https://skia-review.googlesource.com/122943
Reviewed-by: Ravi Mistry <rmistry@google.com>
Commit-Queue: Eric Boren <borenet@google.com>
8 files changed