Upgrade CI images

[ppenzin]

I've had to downgrade Windows CI image in #6829, and we might want to consider Ubuntu 22 and maybe dropping Ubuntu 18.

Platforms we should consider:

• [x] Windows 2022, currently msbuild detection fails, see #6828
• [ ] Ubuntu 22, need to give it a try

I am not sure what is the best way to track new available images, if we let them to be upgraded under our feet (using 'latest'), then we can get surprise errors, like in #6808, but if we don't try them regularly we can easily forget to test on new versions.

[ppenzin]

Trying to enable testing on multiple Windows images in #6832

[ppenzin]

Windows change is in, trying to change Ubuntu images in #6833