Archive the BanyanDB Java Client

The client is deprecated: BanyanDB clients, including the OAP server, use
the BanyanDB Client Proto directly, so there is nothing left to release
here.

- docs.yml: move it out of Database into Archived Repositories, as
  "(Archived) BanyanDB Java Client", dropping the README doc links so the
  card matches the other archived repositories.
- releases.yml: move v0.9.1 into Archived Releases and repoint src/asc/sha512
  at archive.apache.org, since downloads.apache.org only carries current
  releases and this component will not have another one. The Maven
  coordinates are unchanged. Also fixes the "Oct 15th , 2025" date to the
  "Mon. DDth, YYYY" form used everywhere else.

This is also why the Archived Releases section looked broken. It was added
as a bare "- type:" with no list, so the chip and the <h2> rendered but the
grid below them was empty — the section existed with nothing in it. It now
has its first entry.

The card keeps its BanyanDBJavaClient id, so existing links to
/downloads/#BanyanDBJavaClient still resolve.