Use versionless Qt cmake target

This makes it easier to build against both Qt5 and Qt6

GIT_SILENT

autotests/CMakeLists.txt

@@ -9,7 +9,7 @@ set(decorationButtonTest_SRCS
     decorationbuttontest.cpp
     )
 add_executable(decorationButtonTest ${decorationButtonTest_SRCS})
-target_link_libraries(decorationButtonTest kdecorations2 kdecorations2private Qt5::Test)
+target_link_libraries(decorationButtonTest kdecorations2 kdecorations2private Qt::Test)
 add_test(NAME kdecoration2-decorationButtonTest COMMAND decorationButtonTest)
 ecm_mark_as_test(decorationButtonTest)
 
@@ -22,7 +22,7 @@ set(decorationTest_SRCS
     decorationtest.cpp
     )
 add_executable(decorationTest ${decorationTest_SRCS})
-target_link_libraries(decorationTest kdecorations2 kdecorations2private Qt5::Test)
+target_link_libraries(decorationTest kdecorations2 kdecorations2private Qt::Test)
 add_test(NAME kdecoration2-decorationTest COMMAND decorationTest)
 ecm_mark_as_test(decorationTest)
 
@@ -30,6 +30,6 @@ set(decorationShadowTest_SRCS
     shadowtest.cpp
     )
 add_executable(decorationShadowTest ${decorationShadowTest_SRCS})
-target_link_libraries(decorationShadowTest kdecorations2 Qt5::Test)
+target_link_libraries(decorationShadowTest kdecorations2 Qt::Test)
 add_test(NAME kdecoration2-decorationShadowTest COMMAND decorationShadowTest)
 ecm_mark_as_test(decorationShadowTest)

src/CMakeLists.txt

@@ -23,8 +23,8 @@ add_library(KDecoration2::KDecoration ALIAS kdecorations2)
 
 target_link_libraries(kdecorations2
     PUBLIC
-        Qt5::Core
-        Qt5::Gui
+        Qt::Core
+        Qt::Gui
     PRIVATE
         kdecorations2private
         KF5::I18n

src/private/CMakeLists.txt

@@ -18,8 +18,8 @@ add_library(KDecoration2::KDecorationPrivate ALIAS kdecorations2private)
 
 target_link_libraries(kdecorations2private
     PUBLIC
-        Qt5::Core
-        Qt5::Gui
+        Qt::Core
+        Qt::Gui
 )
 
 target_include_directories(kdecorations2private INTERFACE "$<INSTALL_INTERFACE:${KDECORATION2_INCLUDEDIR}>" )