[Qbs] Branch 3.0 created

[Christian Kandeler]

Hi,

we have branched off Qbs 3.0. Scheduled release date for version 3.0.0 
is mid-June (together with Qt Creator 17.0).

We have bumped the major version due to the behavior changes explained 
here: 
https://lists.qt-project.org/pipermail/qbs/2024-August/003178.html. 
Especially with regards to those, we recommend users to try this branch 
with their projects early, so either they or qbs can be fixed in time.

Contributors are requested to push bug fixes and small, zero-risk
improvements to this branch, while features continue to go to master.
Patches currently under review can be moved if they are reasonably close to
finished.


Christian