Use nest/tools/buildah image

.gitlab-ci.yml

 ---
 variables:
   JOBS: 8
-  STORAGE_DRIVER: 'vfs'
 
 default:
-  image: 'quay.io/containers/buildah'
+  image: '${CI_REGISTRY}/nest/tools/buildah:haswell'
   before_script:
-    - 'cp "$REGISTRIES_CONF" /etc/containers/registries.conf'
+    - 'buildah login --username "$CI_REGISTRY_USER" --password "$CI_REGISTRY_PASSWORD" "$CI_REGISTRY"'
 
 'Build haswell':
   stage: 'build'
@@ -14,7 +13,6 @@ default:
   script:
     - 'mkdir debug'
     - 'buildah bud --pull --squash
-                   --creds="${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD}"
                    --security-opt seccomp=unconfined
                    --build-arg GENTOO_STAGE3_TAG=amd64
                    --build-arg EMERGE_DEFAULT_OPTS="--jobs=${JOBS} --usepkg"
@@ -24,5 +22,5 @@ default:
                    -v /nest:/nest
                    -t "${CI_REGISTRY_IMAGE}:haswell" .'
     - 'buildah bud -t "${CI_REGISTRY_IMAGE}/debug:haswell" -f Containerfile.debug .'
-    - 'buildah push --creds="${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD}" "${CI_REGISTRY_IMAGE}:haswell"'
-    - 'buildah push --creds="${CI_REGISTRY_USER}:${CI_REGISTRY_PASSWORD}" "${CI_REGISTRY_IMAGE}/debug:haswell"'
+    - 'buildah push "${CI_REGISTRY_IMAGE}:haswell"'
+    - 'buildah push "${CI_REGISTRY_IMAGE}/debug:haswell"'