CI: hMailServer download broken #23008

Description

Found while working on #22995.

CI downloads hMailServer in .github/scripts/windows/test_task.bat#L117-L124. The download URL returns a CF 403 page, which means its HTML is saved as hMailServer.exe. CI then reports:

The system cannot execute the specified program.

Fatal error: Uncaught com_exception: Failed to create COM object
`hMailServer.Application': Invalid class string

...but doesn't fail. Probably shouldn't be like that. Tests depending on it are then skipped. Also, hMailServer is no longer maintained so instead of fixing the download it probably should be replaced? Not Windows savvy myself so leaving this here for someone else.

cc @SakiTakamachi who has last been working on it a long while ago.