chore: update TypeScript to v6

[sethamus]

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AI acknowledgment

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What is the purpose of this pull request?

This PR updates the repo’s TypeScript tooling to v6.

What changes did you make? (Give an overview)

• bump typescript to v6 in package.json.
• updated the TypeScript module settings to use moduleResolution: "nodenext" and module: "nodenext" instead of the deprecated moduleResolution: "node" setup.
• added rootDir: "lib" to eslint-visitor-keys.

Related Issues

Is there anything you'd like reviewers to focus on?

[nzakas]

Please hold off. There's already a bunch of "Update TypeScript to v6" PRs across the org and we're not even sure we want to upgrade immediately.

[sethamus]

@nzakas Sorry for the PRs! I opened these based on the discussion in my other PR (eslint/eslint#20547 (comment)), which suggested that once TypeScript 6 is officially released, we should update our tooling.

[github-actions]

Hi everyone, it looks like we lost track of this pull request. Please review and see what the next steps are. This pull request will auto-close in 7 days without an update.

[github-actions]

Hi everyone, it looks like we lost track of this pull request. Please review and see what the next steps are. This pull request will auto-close in 7 days without an update.

[nzakas]

Gotcha. @fasttime I'll leave it up to you to review.

[lumirlumir]

Just a note that there are currently some CI failures related to this update.

[fasttime]

The type tests are still failing.

[lumirlumir]

Is there a reason why the named export test was removed?

This test verifies that the named export types exist correctly in the CJS export, so I think it need to be retained.

[lumirlumir]

Suggested change

	} from "../dist/eslint-visitor-keys.cjs";
	} from "eslint-visitor-keys";

I think simply using eslint-visitor-keys would be more accurate here, since the previous test using ../ resolved the type declaration file from the Module declaration surface rather than the CJS format. It was originally linked to lib/index.js and directed to dist/index.d.ts.

Additionally, using eslint-visitor-keys directly would be more beneficial, as it follows the same package-name type resolution path used by real consumers, since it is symlinked in node_modules and consumed like a real package.