dashboard: disable failing repos on misconfigured builders
dashboard: disable failing repos on misconfigured builders

Updates golang/go#32836
Updates golang/go#31567
Updates golang/go#11811

Change-Id: I5443b61cf7732abf906ce2e93eca5408579a55c8
Reviewed-on: https://go-review.googlesource.com/c/build/+/192327
Run-TryBot: Bryan C. Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>
Reviewed-by: Dmitri Shuralyov <d181b7fea0ec87c86ba5a890ab716db52498e3ba@golang.org>
Reviewed-by: Alexander Rakoczy <60c6d277a8bd81de7fdde19201bf9c58a3df08f4@golang.org>

golang/build,golang/build,golang/build,golang/build