Undo custom variable restriction as https://mnt.re/system-image does not...

Undo custom variable restriction as https://mnt.re/system-image does not anymore link to the latest job in 'main'

.gitlab-ci.yml

@@ -12,23 +12,6 @@ variables:
 build:
   script: |
     set -x
-    # Do not allow custom builds in the 'reform' namespace as those can
-    # potentially taint the job artifacts that https://mnt.re/system-image
-    # links to.
-    if [ "$CI_SERVER_HOST" = "source.mnt.re" ] && [ "$CI_PROJECT_NAMESPACE" = "reform" ]; then
-      if [ "$DIST" != "unstable" ]; then
-        echo "Refusing to run pipeline in the 'reform' namespace with DIST not set to 'unstable'" >&2
-        echo "to avoid accidentally tainting the job artifacts that https://mnt.re/system-image links to." >&2
-        echo "Consider running custom pipelines in a fork of reform-system-image under your own username instead." >&2
-        exit 1
-      fi
-      if [ -n "$REFORM_DEBIAN_PACKAGES_BRANCH" ]; then
-        echo "Refusing to run pipeline in the 'reform' namespace with packages from reform-debian-packages'" >&2
-        echo "to avoid accidentally tainting the job artifacts that https://mnt.re/system-image links to." >&2
-        echo "Consider running custom pipelines in a fork of reform-system-image under your own username instead." >&2
-        exit 1
-      fi
-    fi
     apt update -o Acquire::AllowReleaseInfoChange=true -o quiet::ReleaseInfoChange=true
     apt-get --no-install-recommends -y install mmdebstrap ca-certificates e2fsprogs pigz git mount parted apt-utils libarchive-tools python3-apt
     if [ ! -e /proc/sys/fs/binfmt_misc/status ]; then