Fails to build with Plasma 6.3

[jbeich]

Requires porting kwin@953e981807b6

CMake Error at CMakeLists.txt:130 (find_package):
  Could not find a package configuration file provided by "KDecoration2"
  (requested version 6.0.0) with any of the following names:

    KDecoration2Config.cmake
    kdecoration2-config.cmake

  Add the installation prefix of "KDecoration2" to CMAKE_PREFIX_PATH or set
  "KDecoration2_DIR" to a directory containing one of the above files.  If
  "KDecoration2" provides a separate development package or SDK, be sure it
  has been installed.