Support for listing the beta versions

Hello,

Sometime ago I find out about this beautiful URL
https://www.postgresql.org/versions.json which turns out to be really
useful to get the latest available versions of PostgreSQL for automation
process(building and testing mostly) but I sadly find out that the beta
versions aren't listed.

To show first how we use it first we parse and transform the content[1]
into a compatible format that is useful for us (HCL), this is then
updated[2] to make the build process easy and transparent for testing[3] in
other projects.

Does the site provide a way to get the active beta versions or is there a
plan to publish those active beta versions?

I know that most people will ask themself "why is this useful?" but testing
beta versions is really useful to detect bugs and also, having that
automated it's something really useful so people can focus on the bugs not
on remembering to update some configuration file.

Regards!

[1]
https://github.com/cloudnative-pg/postgres-containers/pull/269/files#diff-ff9c56df6264f225b05fd0745304138d7da5a9ac2131474d13a13d99adbe2c09R29
[2]
https://github.com/cloudnative-pg/postgres-containers/blob/main/docker-bake.hcl#L35
[3] https://github.com/cloudnative-pg/postgres-trunk-containers/