Doc: Prefer versioned CMake library targets

The non-versioned one's do miss some properties. It's therefore best
to not advocate using them.

Change-Id: I53645e65ed4de4e0100e59905c024cdfe40be0c5
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

src/concurrent/doc/snippets/CMakeLists.txt

 #! [cmake_use]
 find_package(Qt6 COMPONENTS Concurrent REQUIRED)
-target_link_libraries(mytarget Qt::Concurrent)
+target_link_libraries(mytarget Qt6::Concurrent)
 #! [cmake_use]

src/corelib/doc/snippets/overview/using-qt-core.cmake

 find_package(Qt6 COMPONENTS Core REQUIRED)
-target_link_libraries(mytarget Qt::Core)
+target_link_libraries(mytarget Qt6::Core)

src/dbus/doc/snippets/CMakeLists.txt

 #! [cmake_use]
 find_package(Qt6 COMPONENTS DBus REQUIRED)
-target_link_libraries(mytarget Qt::DBus)
+target_link_libraries(mytarget Qt6::DBus)
 #! [cmake_use]

src/gui/doc/snippets/overview/using-qt-gui.cmake

 find_package(Qt6 COMPONENTS Gui REQUIRED)
-target_link_libraries(mytarget Qt::Gui)
+target_link_libraries(mytarget Qt6::Gui)

src/network/doc/snippets/CMakeLists.txt

@@ -8,5 +8,5 @@ add_executable(mytarget
 
 # ![0]
 find_package(Qt6 COMPONENTS Network REQUIRED)
-target_link_libraries(mytarget Qt::Network)
+target_link_libraries(mytarget Qt6::Network)
 # ![0]

src/opengl/doc/snippets/CMakeLists.txt

 #! [cmake_use]
 find_package(Qt6 COMPONENTS OpenGL REQUIRED)
-target_link_libraries(mytarget Qt::OpenGL)
+target_link_libraries(mytarget Qt6::OpenGL)
 #! [cmake_use]

src/printsupport/doc/snippets/CMakeLists.txt

 #! [cmake_use]
 find_package(Qt6 COMPONENTS PrintSupport REQUIRED)
-target_link_libraries(mytarget Qt::PrintSupport)
+target_link_libraries(mytarget Qt6::PrintSupport)
 #! [cmake_use]

src/sql/doc/snippets/CMakeLists.txt

 #! [cmake_use]
 find_package(Qt6 COMPONENTS Sql REQUIRED)
-target_link_libraries(mytarget Qt::Sql)
+target_link_libraries(mytarget Qt6::Sql)
 #! [cmake_use]

src/testlib/doc/snippets/CMakeLists.txt

 #! [cmake_use]
 find_package(Qt6 COMPONENTS Test REQUIRED)
-target_link_libraries(mytarget Qt::Test)
+target_link_libraries(mytarget Qt6::Test)
 #! [cmake_use]

src/widgets/doc/snippets/CMakeLists.txt

 #! [cmake_use]
 find_package(Qt6 COMPONENTS Widgets REQUIRED)
-target_link_libraries(mytarget Qt::Widgets)
+target_link_libraries(mytarget Qt6::Widgets)
 #! [cmake_use]

src/xml/doc/snippets/CMakeLists.txt

 #! [cmake_use]
 find_package(Qt6 COMPONENTS Xml REQUIRED)
-target_link_libraries(mytarget Qt::Xml)
+target_link_libraries(mytarget Qt6::Xml)
 #! [cmake_use]