Bump KF5 min version & define KDE_COMPILERSETTINGS_LEVEL

This is what dolphin currently requires

CMakeLists.txt

@@ -10,7 +10,8 @@ set(RELEASE_SERVICE_VERSION "${RELEASE_SERVICE_VERSION_MAJOR}.${RELEASE_SERVICE_
 project(dolphin-plugins VERSION ${RELEASE_SERVICE_VERSION})
 
 set(QT_MIN_VERSION "5.15.0")
-set(KF5_MIN_VERSION "5.83.0")
+set(KF5_MIN_VERSION "5.90.0")
+set(KDE_COMPILERSETTINGS_LEVEL "5.84")
 
 find_package(ECM ${KF5_MIN_VERSION} REQUIRED NO_MODULE)
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake" ${ECM_MODULE_PATH})