chore: 🤖 add back lighthouse-core scripts to npm package

[r0mflip]

Issues: #6150

Summary
Solves #6150

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[r0mflip]

I signed it!

[googlebot]

CLAs look good, thanks!

[paulirish]

nice. thanks for making the PR.
one idea though..

[paulirish]

below a bit is this line:

!lighthouse-core/scripts/manual-chrome-launcher.js

can you add a direct refrence to the download-chrome sh right after it?

i'd rather do that than allowlist this whole folder.

[r0mflip]

That sounds good, thanks. Please verify.