QtWebKit: update build dependencies for RC2
QtWebKit: update build dependencies for RC2

Drop (comment out) these build requirements:
- QtLocation
- Qt3D
- QtSensors

None of the above are part of "essential" modules, and as such QtWebKit
no longer has hard dependencies on any of them.

Add these:
- QtNetwork
- ruby

Ruby is required for offlineasm/macroassembly code generation.

bostik/qt5-specs,bostik/qt5-specs