The scripts and instructions have been nonfunctional at least since
PostgreSQL 10 (commit 510074f9) and
nobody has stepped up to fix them.  So right now just remove them until
someone wants to resurrect them.

Discussion: https://www.postgresql.org/message-id/flat/B74C0219-6BA9-46E1-A524-5B9E8CD3BDB3%40yesql.se