Keycloak support is broken due to unmaintained library

Description

TL;DR: This scraper used to support Keycloak SSO, but now it no longer does (unless you're running a very old Keycloak).

Support for Keycloak SSO was added in #73 by @spahrson and it is a great addition that we're super appreciative of 🎉

Unfortunately, the python-keycloak-client library used to add this functionality is de-facto unmaintained, which is a problem because Keycloak introduced a breaking change in Keycloak v17 which changed the URLs under which to find the OIDC endpoints.

Given that:

• The Keycloak 17.0 release dates from February 2022
• Releases prior to 17 (aka pre-Quarkus releases) have been deprecated ever since
• The latest Keycloak release is 25.0.1

The end result is that this no longer supports keycloak SSO in a meaningful way.

I was hoping we could get that support back.
Ways to do so include:

• Migrate to a maintained Keycloak library
• Monkey-patch the existing library to strip the leading auth/ prefix from the URLs

Other
I'm not familiar with the Python ecosystem, so I cannot really offer to do it myself. But I am happy to help testing, or update docs, or help get this done somehow.

The issue names no repository files or tests; start by locating the existing Keycloak SSO integration and its python-keycloak-client dependency. Reproduce the failure against a current Keycloak release, then evaluate the maintained python-keycloak migration and the documented auth/URL-prefix workaround. Done means Keycloak SSO works with supported releases and the relevant setup is covered.