Merge topic 'ci-windows'

3d4073b129 gitlab-ci: Try upstream ninja development branch in a Windows nightly job
bbb2664547 gitlab-ci: Add wix, cmake, and ninja to PATH incrementally on Windows
658009b6fe ci: Fix vcvarsall.ps1 environment variable lookup

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !6732