ci: move 1.20 branch CI to Windows 2022 server image
Need to get rid of the remaining 1809 users, so we can re-purpose that runner capacity to 2022.
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
Need to get rid of the remaining 1809 users, so we can re-purpose that runner capacity to 2022.