Add Kudzu to buildbucket.config Also, remove Zephyr. Bug: b/306169290 Change-Id: I02428916dfbffbeda6cb26c88d242b51dd89fe78 Reviewed-on: https://pigweed-review.googlesource.com/c/Pigweed-Base/+/176862 Reviewed-by: Anthony DiGirolamo <tonymd@google.com>