Adapt build system for building against qt6

CMakeLists.txt

@@ -3,7 +3,7 @@ project(plasma-nano)
 # minimal requirements
 cmake_minimum_required(VERSION 3.16)
 set (QT_MIN_VERSION "5.15.0")
-set(KF5_MIN_VERSION "5.86")
+set(KF5_MIN_VERSION "5.90")
 set(KDE_COMPILERSETTINGS_LEVEL "5.82")
 
 set(CMAKE_CXX_STANDARD 17)
@@ -28,7 +28,7 @@ include(KDEGitCommitHooks)
 include(GenerateExportHeader)
 include(FeatureSummary)
 
-find_package(Qt5 ${QT_MIN_VERSION} CONFIG REQUIRED Core Gui Qml Quick)
+find_package(Qt${QT_MAJOR_VERSION} ${QT_MIN_VERSION} CONFIG REQUIRED Core Gui Qml Quick)
 find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS Plasma WindowSystem Wayland)