Make it compile against qt6

CMakeLists.txt

@@ -18,7 +18,11 @@ include(FindPkgConfig)
 include(FeatureSummary)
 
 
-find_package(Qt5 5.15 REQUIRED COMPONENTS Core)
+find_package(Qt${QT_MAJOR_VERSION} 5.15 REQUIRED COMPONENTS Core)
+if (QT_MAJOR_VERSION STREQUAL "6")
+    find_package(Qt6Core5Compat)
+endif()
+
 find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS
     ConfigWidgets
     XmlGui
@@ -77,7 +81,7 @@ endif()
 
 install(FILES
     solid_camera.desktop
-    DESTINATION ${DATA_INSTALL_DIR}/solid/actions)
+    DESTINATION ${KDE_INSTALL_DATADIR}/solid/actions)
 
 install(FILES
     org.kde.kamera.metainfo.xml

kioslave/CMakeLists.txt

@@ -10,7 +10,7 @@ add_library(kio_kamera MODULE ${kio_kamera_PART_SRCS})
 include_directories(${GPHOTO2_INCLUDE_DIRS} ${CMAKE_BINARY_DIR})
 
 target_link_libraries(kio_kamera
-    Qt::Core
+    Qt${QT_MAJOR_VERSION}::Core
     KF5::KIOCore
     KF5::I18n
     KF5::ConfigCore