fix: make env value type unknown

[dword-design]

Currently only string is allowed as values for env. But the variables will be stringified by Node.js, so actually anything can be passed.

I removed a test that imho isn't needed anymore. Alternatively, env could get a generic type arg, but as long as the type isn't used in any way in the lib, there isn't a need for it imho.

[ehmicky]

Hi @dword-design,

This makes sense to me. Although arguably, some might consider relying on implicit transtyping to be bad practice, do we still want to allow it with our types?

What are your thoughts on this @sindresorhus?

[sindresorhus]

It's intentionally strict. That's the point of using TS. Lots of things are implicitly coerced in JS, but the types should not reflect that. So I would not merge this.

[dword-design]

It's fine for me not to merge it. At least the discussion is here in case there are people asking. Alternatively, I thought about having the primitive types like number or boolean in it but again, discusable.

[ehmicky]

Thanks for your understanding @dword-design. 🙏
If someone else has some feedback on this, please feel free to continue discussing here or on a new issue.