Revert "Again "Temporary pin reference image""

As per llvm/llvm-project#101201 (comment)
This reverts commit dbff0be.

Change-Id: Iad876f3fba7fdb4b2d60908c4728c5c8f1124ca9

Author: TimotheusBachinger

defines/dev-images/reference-image-id

@@ -1,5 +1,4 @@
 #!/usr/bin/env bash
-# shellcheck disable=SC2317
 
 # This script builds a 'reference image' (formerly known as IMAGE_TESTING)
 # and returns its image ID
@@ -10,9 +9,6 @@
 # @DOCKER_REGISTRY: the Docker registry to connect to
 # @BASE_BUILD_IMAGE: overrides the whole base image specifier
 
-echo "artifacts.lan.tribe29.com:4000/ubuntu-22.04:llvm-pin"
-exit 0
-
 set -e
 
 : "${REFERENCE_IMAGE_DISTRO:="ubuntu-22.04"}"