b277537cbe
We moved to the major release branches with a `.x` suffix and forgot to
adjust this workflow to run on branches like `27.x`.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
(cherry picked from commit 987befaeac)
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>