Change ci vars to use group one's (#11281)

substrate/.gitlab-ci.yml

@@ -599,7 +599,7 @@ build-rustdoc:
     - echo "${PRODUCT} version = ${VERSION}"
     - test -z "${VERSION}" && exit 1
   script:
-    - test "$DOCKER_HUB_USER" -a "$DOCKER_HUB_PASS" ||
+    - test "$Docker_Hub_User_Parity" -a "$Docker_Hub_Pass_Parity" ||
         ( echo "no docker credentials provided"; exit 1 )
     - buildah bud
         --format=docker
@@ -608,8 +608,8 @@ build-rustdoc:
         --tag "$IMAGE_NAME:$VERSION"
         --tag "$IMAGE_NAME:latest"
         --file "$DOCKERFILE" .
-    - echo "$DOCKER_HUB_PASS" |
-        buildah login --username "$DOCKER_HUB_USER" --password-stdin docker.io
+    - echo "$Docker_Hub_Pass_Parity" |
+        buildah login --username "$Docker_Hub_User_Parity" --password-stdin docker.io
     - buildah info
     - buildah push --format=v2s2 "$IMAGE_NAME:$VERSION"
     - buildah push --format=v2s2 "$IMAGE_NAME:latest"