vendor: update moby/buildkit

Update modules:

  go mod edit -require github.com/moby/buildkit@master
  go mod tidy -compat=1.17 && ./hack/update-vendor

Signed-off-by: Justin Chadwell <me@jedevc.com>

vendor/github.com/containerd/continuity/AUTHORS

@@ -1,8 +1,6 @@
-Aaron Lehmann <aaron.lehmann@docker.com>
+Aaron Lehmann <alehmann@netflix.com>
 Akash Gupta <akagup@microsoft.com>
 Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
-Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
-Akihiro Suda <suda.kyoto@gmail.com>
 Andrew Pennebaker <apennebaker@datapipe.com>
 Brandon Philips <brandon.philips@coreos.com>
 Brian Goff <cpuguy83@gmail.com>
@@ -10,9 +8,9 @@ Christopher Jones <tophj@linux.vnet.ibm.com>
 Daniel, Dao Quang Minh <dqminh89@gmail.com>
 Darren Stahl <darst@microsoft.com>
 Derek McGowan <derek@mcg.dev>
-Derek McGowan <derek@mcgstyle.net>
 Edward Pilatowicz <edward.pilatowicz@oracle.com>
 Fu Wei <fuweid89@gmail.com>
+Gabriel Adrian Samfira <gsamfira@cloudbasesolutions.com>
 Hajime Tazaki <thehajime@gmail.com>
 Ian Campbell <ijc@docker.com>
 Ivan Markin <sw@nogoegst.net>
@@ -20,20 +18,18 @@ Jacob Blain Christen <jacob@rancher.com>
 Justin Cormack <justin.cormack@docker.com>
 Justin Cummins <sul3n3t@gmail.com>
 Kasper Fabæch Brandt <poizan@poizan.dk>
+Kazuyoshi Kato <katokazu@amazon.com>
 Kir Kolyshkin <kolyshkin@gmail.com>
 Michael Crosby <crosbymichael@gmail.com>
-Michael Crosby <michael@thepasture.io>
 Michael Wan <zirenwan@gmail.com>
 Mike Brown <brownwm@us.ibm.com>
 Niels de Vos <ndevos@redhat.com>
-Phil Estes <estesp@amazon.com>
 Phil Estes <estesp@gmail.com>
-Phil Estes <estesp@linux.vnet.ibm.com>
 Sam Whited <sam@samwhited.com>
 Samuel Karp <me@samuelkarp.com>
 Sebastiaan van Stijn <github@gone.nl>
 Shengjing Zhu <zhsj@debian.org>
-Stephen J Day <stephen.day@docker.com>
+Stephen J Day <stevvooe@gmail.com>
 Tibor Vass <tibor@docker.com>
 Tobias Klauser <tklauser@distanz.ch>
 Tom Faulhaber <tffaulha@amazon.com>