Add ct-staging to SKFE.
Add ct-staging to SKFE.

Change-Id: I4d5aba61d3f627decc5ba638e4bfafc984932cad
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/278464
Reviewed-by: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>
Commit-Queue: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>
Commit-Queue: Weston Tracey <e7e27cb74e46abd7b999223aa4f27901ab7e58c6@google.com>
Auto-Submit: Weston Tracey <e7e27cb74e46abd7b999223aa4f27901ab7e58c6@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