Replace `concat-stream` with `text()` from `node:stream/consumers`

[ChristianMurphy]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and discussions and couldn’t find anything (or linked relevant results below)

Problem

Node now ships text() in node:stream/consumers, which reads a whole stream into a string.
That's all we use concat-stream for, reading streamIn in lib/file-set-pipeline/stdin.js.
Every remark-cli/rehype-cli/etc user installs concat-stream, plus its transitive tree.

Current solutions

• keep concat-stream

Proposed solutions

• swap concat-stream for text() from node:stream/consumers

text() was added in Node 16.7.0, so it fits our policy of keeping ^11 compatible with Node 16, and doesn't need to wait for a major.

Things to watch for:

• text() rejects when the stream errors, concat-stream never calls back, so that path needs wiring into next(error) and a test to keep coverage at 100%

Thoughts?

[wooorm]

yeah sounds good! I think there’s a bunch of other places across the ecosystem this can be done too!