Release [2023.04] - Hard feature freeze now effective

Dear RIOTers,

we have created the 2023.04 release branch, so we are now officially in feature freeze. This means from now only bugfixes will be backported to the 2023.04-branch. If anyone has any bugfixes or documentation improvements that they feel should be part of this release please let me know.

New features can still be merged into master during this period.

The test tracking issue of RC1 is opened. Help with testing and resources for the testing is as always very welcome. Most of the testing is automated, but some stuff still needs to be run manually. So if you want to help, please put your name after the corresponding item in the linked issue to streamline the testing efforts.

Thanks all for the awesome work!

Cheers, Kevin & José