workflows/dispatch-build-bottle: run prepare job as root in container

[ZhongRuoyu]

This unfortunately didn't work due to permission issues: https://github.com/Homebrew/homebrew-core/actions/runs/10809935351/job/29986089580

A workaround could be to set options: --user root, but brew ruby will probably refuse to run as root.

Reverts #186614

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[ZhongRuoyu]

A workaround could be to set options: --user root, but brew ruby will probably refuse to run as root.

Actually, that should actually work in Docker. Do we want that though? I'm not sure.

[carlocab]

Actually, that should actually work in Docker. Do we want that though? I'm not sure.

Should be fine for the prepare job. But I'm happy to change my position if someone has a strong objection.

[carlocab]

Let's ship this for now since this is blocking bottling.

[carlocab]

Note that the alternative to this is to sudo chown "${GITHUB_OUTPUT}", but I don't know how to translate that to JavaScript. 🥲

Hopefully someone else can tell us!

[Bo98]

You don't need root if you move setup-homebrew to run first. It applies the necessary permission fixes to make everything work.