Using nimterop in MSYS2 Bash environment on Windows
When developing with Nim on Windows over the last year+, my preferred setup (for compiling, etc.) has become a Bash shell in [MSYS2's UCRT64 environment](https://www.msys2.org/docs/environments/). It's nice because you get a very Linux-like experience while developing, but you're building native Windows programs.

Currently, I'm trying out nimterop for a project but have run into a snag on Windows (it's working fine on Linux and macOS). Consider these lines:

https://github.com/nimterop/nimterop/blob/master/nimterop/build/tools.nim#L209-L211

In an MSYS2 Bash shell, I do want `-G"MSYS Makefiles"`; but `sh -c uname -a` yields `MINGW64_NT-10.0-19043`, so nimterop instead invokes cmake with `-G"MinGW Makefiles"`, which hangs indefinitely. I'm not sure why it hangs, but that's the behavior I get on several Windows machines, including  Windows in GitHub Actions.

I can hack nimterop by changing L210 to:
```nim
if true: # uname.contains("msys"):
```
And it works: the cmake step no longer hangs.

I'm happy to submit a PR with a proper solution, but I'm not sure yet what's the best approach. Any ideas?