appveyor: Add VS2022 builds
Upgrade to use the "Visual Studio 2022" container image.
- Retain VS2019 builds
- Add VS2022 builds
- Cygwin and MinGW builds use the "Visual Studio 2022" container image (no functional change, both images have the same versions)
- MinGW build updated to use MSYS2 with
zlib
andlibjpeg-turbo
dependencies installed with pacman
Edited by Roger Leigh