[Development] Qt 6.3 initial schedule

[Jani Heikkinen]

Hi All,

Here is the proposal for Qt 6.3 schedule:

- Qt 6.3 Feature Freeze 10th December 2021
- Qt 6.3 Alpha release 16th December 2021
- Qt 6.3 Beta1 release 12th January 2022
- Qt 6.3 RC 2nd March 2022               
- Qt 6.3 Final release 16th March 2022

The idea behind the schedule:
* Release Qt 6.3.0 ~ 6 months after Qt 6.2.0
* Have the FF as late as possible but on the other hand early enough to
   ** trust we can keep the schedule
   ** get the Alpha release out before Christmas

Any comments/objections?

Br,
Jani Heikkinen
Release Manager