use KF6Kirigami instead of KF6Kirigami2
Cmake shows that KF6Kirigami2 is deprecated:
CMake Warning (dev) at /home/bogdan/kde/usr/lib/cmake/KF6Kirigami2/KF6Kirigami2Config.cmake:28 (message): find_package(KF6Kirigami2) is deprecated, use find_package(KF6Kirigami) instead