qt5-webengine needs deprecated version of Python 2.7
Yeah, we are well aware of it, but webengine/chromium are beasts, and the hope is, that upstream fixes that in time.
A few URLs for reference:
*** Bug 249801 has been marked as a duplicate of this bug. ***
That deprecation warning has now been (or will shortly be) removed. So not "fixed" because that build-time-dependency on Python 2.7 still exists, but less annoying for users.