core(fr): add artifact dependency support

[patrickhulce]

Summary
Adds config and runner support for artifact dependencies, see #12017 for expected usage examples and discussion. I know this is a monster PR, but it truly is the minimal set of artifact dependency support that is validated, typechecked, and tested (there isn't even a single gatherer that's upgraded for dependency support in here! 🤯). I do think it's rather helpful to see it all come together rather than jump between different related PRs by potential different reviewers, but we do have few options if we want to reduce the line count.

• Split the config support from runner support and just break some types and/or add temporary meaningless types
• Land the timespan/snapshot runner test updates separately
• Land the config validation pieces separately (everything would typecheck and work but you could create invalid dependency relationships)

Related Issues/PRs
ref #11313
ref #12017

[adamraine]

Why does this need to be async?

[patrickhulce]

would you prefer to convert the final await to a .then?

or asking why we want to convert the artifact dependencies from promises to the resolved artifacts?

[adamraine]

or asking why we want to convert the artifact dependencies from promises to the resolved artifacts?

This. I don't really have a suggestion, just trying to understand this.

[patrickhulce]

We want to pass the artifact directly to a gatherer that is depending on it so the burden doesn't fall on consumers to await and handle any errors. Resolving any errors ahead of time also means every individual gatherer doesn't have to remap their dependencies' errors. We do a similar thing for audits today, pass them artifacts, not promises of artifacts and remap their artifacts when they fail.

lighthouse/lighthouse-core/runner.js

Lines 323 to 339 in b292ae0

	// If artifact was an error, output error result on behalf of audit.
	if (artifacts[artifactName] instanceof Error) {
	/** @type {Error} */
	// @ts-expect-error An artifact *could* be an Error, but caught here, so ignore elsewhere.
	const artifactError = artifacts[artifactName];
	Sentry.captureException(artifactError, {
	tags: {gatherer: artifactName},
	level: 'error',
	});
	log.warn('Runner', `${artifactName} gatherer, required by audit ${audit.meta.id},` +
	` encountered an error: ${artifactError.message}`);
	// Create a friendlier display error and mark it as expected to avoid duplicates in Sentry
	const error = new LHError(LHError.errors.ERRORED_REQUIRED_ARTIFACT,
	{artifactName, errorMessage: artifactError.message});

[patrickhulce]

thanks for the review! :)

[patrickhulce]

would you prefer to convert the final await to a .then?

or asking why we want to convert the artifact dependencies from promises to the resolved artifacts?