[infra] Fix Infra-PerCommit-CreateDockerImage
[infra] Fix Infra-PerCommit-CreateDockerImage

"go get" is unnecessary (dependencies are synced automatically during
the build) and causes go.mod to be "cleaned up", resulting in pinned
versions being lost and conflicting versions to be used instead.

Change-Id: I0b758cfd3e3329e3a64d2f6e39ad9e335e7a56c3
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/306837
Reviewed-by: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@google.com>
Commit-Queue: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@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