Qt6: Configure fails for Qt 6.10 (Qt6::CorePrivate - target was not found.)

[codeling]

When trying to build the PythonQt within the Slicer superbuild with Qt 6.10 (based on pull request Slicer/Slicer#8825), configure of PythonQt within CTK build fails with

CMake Error at CMakeLists.txt:348 (target_link_libraries):
  Target "PythonQt" links to:

    Qt6::CorePrivate

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.

Qt 6.10 introduces build system changes: To access private libraries, an according ...Private component has to be added. I have prepared a pull request and hope it is pointed at the correct branch in this repository!

[jamesobutler]

Closed by #95.