citemplate: avoid the need to upgrade buildah in docker build

We only need the newer version from the image, to support
the --arch arg, but we don't really use it yet so we
could live without it.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-ci/-/merge_requests/318>

gitlab/ci_template.yml

@@ -205,8 +205,6 @@ variables:
     # using the vfs driver, and this causes errors.
     - sed -i '/^mountopt =.*/d' /etc/containers/storage.conf
 
-    - dnf upgrade -y buildah skopeo jq runc
-
     - *check_image_exists
 
     # This part of the job should only ever be possible to be reach in a gst-ci fork
@@ -223,7 +221,6 @@ variables:
     - >
       buildah bud
       --build-arg DEFAULT_BRANCH=$GST_UPSTREAM_BRANCH
-      --arch=${ARCH:=amd64}
       --label ci.job_id=$CI_JOB_ID
       --label pipeline.url=$CI_PIPELINE_URL
       --label git.ref_name=$CI_COMMIT_REF_NAME