[skfe] envoy not longer supports a 'latest' tag.
[skfe] envoy not longer supports a 'latest' tag.

Change-Id: I710d365908a0cb01e115a63b3631db7250ec386f
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/284517
Reviewed-by: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot