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• I have searched for related issues and found none that match my proposal.
• I have searched the current rule list and found no rules that match my proposal.
• I have read the FAQ and my problem is not listed.

Relevant Package

utils

My proposal is suitable for this project

• I believe my proposal would be useful to the broader TypeScript community (meaning it is not a niche proposal).

Description

Splitting out of #8211 / #8211 (comment):

API Users (mainly those that use utils/ts-eslint)

• Switch Linter to flat config by default

We'd need to look more into the difference between the before and after here as to whether it actually makes a difference for consumers of our package. If it doesn't then all good we can tick and move on! If it does then we need to figure out a path forward here with the types. EG how can we support types that depend on the version of eslint the user has installed?

In summary: we need to update the TSESLint.Linter class within @typescript-eslint/utils/ts-eslint to have the same default behavior as the core ESLint.Linter class.

Additional Info

This isn't a good first issue. Someone who's already familiar with the classes & utilities in question should tackle this.

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