[Development] Where's the dev headers check and -Werror build?

[Thiago Macieira]

https://codereview.qt-project.org/c/qt/qtbase/+/309273 (dev) integrated 
without error. But the cherry-pick of the exact same change to 5.15 in 
https://codereview.qt-project.org/c/qt/qtbase/+/311495 failed due to -Werror.

So where is the dev one?
-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel DPG Cloud Engineering