Time to support qt 6.2.x

[awesomeerictech]

Please add support for qt 6.2.x

[ekke]

sorry - this will take some time.
I just ported my projects to qt 5.15
now have to do many work to refactor and prepare for qt6
all this must be done for all my customer projects, too
for me I have decided to start with qt 6.4 to have enough time . also there are many things fixed / added for 6.3 and 6.4