Version: Deno 2.1.3

Hi there 👋

I'm currently experiencing an issue where Deno's node:child_process polyfill is always passing the parent process's environment to spawned subprocesses even when the env option is provided. On Node it looks like the correct behaviour is for the parent environment to be inherited only when env isn't specified, otherwise only the values from env are passed to the environment.

For example, the code:

import child_process from 'node:child_process'

child_process.spawnSync('env', { env: { test: 'test' } }).stdout.toString('utf8')

When run on Node only outputs 'test=test\n' but when run on Deno outputs the full parent environment in addition to test=test.

I've had a go at fixing this in #27340 😄