Streams are not destroyed when the process exits early

[ehmicky]

When users pass a value like a transforms, web streams, etc. to the stdin/stdout/stderr options, we create a Node.js stream under-the-hood to perform our internal piping logic.

When the process fails on spawn (e.g. the command does not exist), those internally created Node.js streams are currently not destroyed. This wastes resources, i.e. is a memory leak.