[CI] zlib fails to download on Windows

[pcolberg]

Windows build fails on #94:

Invoke-WebRequest: D:\a\fpga-runtime-for-opencl\fpga-runtime-for-opencl\scripts\install_zlib.ps1:18
Line |
  18 |  Invoke-WebRequest $archive_url -OutFile $archive
     |  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     |   404 Not Found  Not Found The requested URL was not found on this server. Additionally, a 404 Not
     | Found error was encountered while trying to use an ErrorDocument to handle the request.