Windows: every child cargo process show a black console window

[ogoffart]

On Windows, loading the metadata and other child cargo processes show a cmd window.

Seems like we need to add some flags to every command so they don't show https://stackoverflow.com/questions/59692146/is-it-possible-to-use-the-standard-library-to-spawn-a-process-without-showing-th

The problem is that some sub processes are started from 3rd party crates