Allow to build against qt-6.5.

Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -223,7 +223,7 @@ find_soft_mandatory_package(ENABLE_QT5 Qt5Xml ${QT5_VE
 find_soft_mandatory_package(ENABLE_QT5 Qt5Widgets ${QT5_VERSION})
 find_soft_mandatory_package(ENABLE_QT5 Qt5Test ${QT5_VERSION})
 
-set(QT6_VERSION "6.2")
+set(QT6_VERSION "6")
 SET(QT_NO_CREATE_VERSIONLESS_TARGETS ON)
 find_soft_mandatory_package(ENABLE_QT6 Qt6Core ${QT6_VERSION})
 find_soft_mandatory_package(ENABLE_QT6 Qt6Gui ${QT6_VERSION})
