fix: Use a pnpm preinstall script to fix catch-22 in next binary creation

[bgw]

We've had a longstanding issue where you'd have to run pnpm i twice on a fresh checkout because pnpm wouldn't set up binary symlinks until after the binary exists, but the binary wouldn't exist until after pnpm build was done:

https://github.com/vercel/next.js/blob/canary/.github/workflows/build_reusable.yml#L303-L311

This solves that problem using a pnpm preinstall script that creates stub binaries for these files if they don't exist yet (because we haven't run pnpm build).

Test Plan

git clean -fxd
pnpm i
pnpm build
pnpm test-start test/e2e/app-dir/next-image/
pnpm test-start-turbo test/e2e/app-dir/next-image/

I tested this both locally and inside of a fresh ubuntu VM.

Running pnpm next after pnpm i but before pnpm build gives a helpful error message:

[bgw]

• fix: Use a pnpm preinstall script to fix catch-22 in next binary creation #91016 👈 (View in Graphite)
• canary

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[bgw]

I'm not sure why, and codex wasn't able to figure it out either, but when I was running pnpm i inside of a fresh ubuntu VM, it was trying to modify the pnpm-lock.yaml unless these flags were set due to some sort of workspace isolation issue.

But either way, these flags seem like a small improvement here.