Fix flaky MSMPI installation in windows builds

[vicentebolea]

It attempts to solve windows setup errors in CI such as:

Downloading Microsoft MPI Runtime 10.1.1
  Invoke-WebRequest: D:\a\ADIOS2\ADIOS2\gha\scripts\ci\gh-actions\windows-setup.ps1:29
  Line |
    29 |      Invoke-WebRequest "$baseurl/msmpisetup.exe" -OutFile $msmpisetup
       |      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       | Authentication failed, see inner exception.
  
  Error: Process completed with exit code 1.

As seen here: #3619

[vicentebolea]

Merging without review since it is a small CI change and in order to check that this works is by having it in master for a few days.