We are going to run test suite twice with qtwebview, with
different backends on windows. Therefore install
webview2 to build plugin also on other nodes.
Task-number: QTBUG-128447
Task-number: QTBUG-75747
Pick-to: 6.10
Change-Id: I88da09eb9bf9e58f630ed65071d33bd4a89ac094
Reviewed-by: Toni Saario <toni.saario@qt.io>