Adapt build system for building against qt6

CMakeLists.txt

@@ -51,7 +51,7 @@ set(KDEPIM_LIB_SOVERSION "5")
 
 
 set(QT_REQUIRED_VERSION "5.15.2")
-find_package(Qt5 ${QT_REQUIRED_VERSION} CONFIG REQUIRED Widgets Test DBus PrintSupport)
+find_package(Qt${QT_MAJOR_VERSION} ${QT_REQUIRED_VERSION} CONFIG REQUIRED Widgets Test DBus PrintSupport)
 set(LIBKDEPIM_LIB_VERSION "5.19.40")
 set(LIBGRANTLEETHEME_LIB_VERSION "5.19.40")
 set(PIMCOMMON_LIB_VERSION "5.19.40")

kontactplugin/CMakeLists.txt

@@ -24,4 +24,4 @@ target_link_libraries(kontact_kaddressbookplugin
 kcoreaddons_desktop_to_json(kontact_kaddressbookplugin kaddressbookplugin.desktop SERVICE_TYPES kcmodule.desktop)
 
 install(TARGETS kontact_kaddressbookplugin DESTINATION ${KDE_INSTALL_PLUGINDIR}/kontact5)
-install(FILES kaddressbookplugin.desktop DESTINATION ${KDE_INSTALL_KSERVICES5DIR}/kontact)
+install(FILES kaddressbookplugin.desktop DESTINATION ${KDE_INSTALL_KSERVICESDIR}/kontact)

src/CMakeLists.txt

@@ -116,7 +116,7 @@ target_link_libraries(kaddressbookprivate
     KF5::XmlGui
     KF5::JobWidgets
     KF5::KIOWidgets
-    Qt::PrintSupport
+    Qt${QT_MAJOR_VERSION}::PrintSupport
     KF5::AkonadiSearchDebug
     KF5::I18n
     KF5::Prison