ci: Attempt to fix broken Windows CI

https://gitlab.freedesktop.org/nirbheek/orc/-/pipelines/169274

Update to latest image and use the gstreamer runner tag. Matches the
gst-ci template.

Also try to make MSYS2 CI more resilient by following:
https://github.com/msys2/setup-msys2/blob/master/main.js#L98

Part-of: <gstreamer/orc!42>
5 jobs for uwp-virtualallocfromapp in 5 minutes and 16 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Build
passed debian sid #3378992

00:01:05

passed msys2 #3379168
docker windows 1809 gstreamer-windows

00:03:41

passed vs2017 amd64 #3378993
docker windows 1809 gstreamer-windows

00:01:34

passed vs2017 x86 #3378994
docker windows 1809 gstreamer-windows

00:01:17

failed msys2 #3378995
docker windows 1809 gstreamer-windows

00:01:29