Issue with ca-certificates-java and backports autobuilders

Hi,

Over at
https://buildd.debian.org/status/package.php?p=nncp&suite=bookworm-backports
I can see that nncp 8.9.0 is only installed on bookworm-backports on the
arch I built it for (amd64).  All others are blocked with:

Dep-Wait (ca-certificates-java (>= 20230620~deb12u1))

I'm trying to figure out the problem; that package is arch: all and that
version is in bookworm-updates per
https://packages.debian.org/search?keywords=ca-certificates-java .

nncp uses plantuml as part of the doc build, which is a java program.
plantuml depends on default-jre-headless, which pulls in openjdk-17-jre-headless.

openjdk-17-jre-headless -- including the version in security -- only
depends on ca-certificates-java (>= 20190405~), and version 20230103 is
in bookworm itself.

In other words, I can't come up with any reason that this is in
dep-wait:

- there is no reason it should need the listed version of
  ca-certificates-java;

- and even if it did, that version is in bookworm-updates anyhow.

Any ideas?

Thanks,

John