Matching libpq-dev-Package missing in Debian-Repo?

Hi,

I'm using Postgres-Server in Debian Bullseye (13.7-0+deb11u1 from
http://security.debian.org/debian-security) and Pgadmin4 (6.10 from
https://ftp.postgresql.org/pub/pgadmin/pgadmin4/apt/bullseye)

Server and PgAdmin4 are working great (thanks for all the programming
and packaging work!).

I don't know if that one is strictly necessary for pgadmin4, but libpq5
is installed as 14.3-1.pgdg110+1 from
https://ftp.postgresql.org/pub/pgadmin/pgadmin4/apt/bullseye instead of
13.7-0+deb11u1 from http://security.debian.org/debian-security. To
prevent the update I have to Force-install the old version and apt-mark
hold the package.

But now I'm unable to install libpq-dev, because there seems to be none
at https://ftp.postgresql.org/pub/pgadmin/pgadmin4/apt/bullseye and the
one from http://security.debian.org/debian-security isn't installable
because exact matching versions between libpq5 and libpq-dev are enforced!

Am I missing something or wouldn't it make sense to publish a matching
libpq-dev on https://ftp.postgresql.org/pub/pgadmin/pgadmin4/apt/bullseye?

Thanks and bye..,
Michael