Building QtCreator Plugin with provided binaries

Use Case:

Downloading QtCreator  and QtQreator dev archives, extraxting into a subfolder.

Build a plugin with provided skript "build_plugin.py".

The deployed QtCreator Cmake files try and reference a Qt 5.15.2 Version, but QtCreator is builded against a Qt6 Version. Assumption is Qt Cmake Files under /lib/cmake/QtCreator/ are outdated / not up-to-date ?

Plugins should be developped against Qt6 Version?
Also in the github actions files and some other examples xmlpatterns seems referenced, which ist not supported any more with 6.2?

Please provide a valid/up-to-date doc for writing/building custom plugins under doc/ and keep the templates valid/up to date!