feat: remove RuleTester in /utils in favour of the new /rule-tester package

[bradzacher]

BREAKING CHANGE:
Removes RuleTester from the @typescript-eslint/utils/eslint-utils package in favour of the new @typescript-eslint/rule-tester package.

PR Checklist

• Steps in Contributing were taken

Overview

Migrates our codebase to use the package added in #6777 as a thorough test of the fork to make sure it works as expected.

• Most changes were just to the file imports
• Some tests I was able to remove the filename config. The old rule tester did file.tsx for JSX files - which actually didn't work at all because TS wouldn't pick up both file.ts and file.tsx.
• I removed the batchedSingleLineTests util from some places - but it's probably worth removing it entirely in future (once I add snapshot tests we shouldn't need it)

[typescript-eslint]

Thanks for the PR, @bradzacher!

typescript-eslint is a 100% community driven project, and we are incredibly grateful that you are contributing to that community.

The core maintainers work on this in their personal time, so please understand that it may not be possible for them to review your work immediately.

Thanks again!

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✅ Successfully ran 32 targets

• Node 18 - nx test eslint-plugin
• Node 14 - nx test eslint-plugin --coverage=false
• nx run-many --target=lint --parallel
• nx run-many --target=build --projects=website-eslint,website
• Node 18 - nx test typescript-estree
• Node 18 - nx test scope-manager
• Node 18 - nx test parser
• Node 18 - nx test type-utils
• Node 18 - nx test rule-schema-to-typescript-types
• Node 18 - nx test utils
• Node 18 - nx test visitor-keys
• Node 18 - nx run types:build
• Node 18 - nx test repo-tools
• Node 14 - nx test typescript-estree --coverage=false
• nx run-many --target=typecheck --parallel
• nx run integration-tests:test
• Node 18 - nx test eslint-plugin-tslint
• Node 14 - nx test eslint-plugin-tslint --coverage=false
• Node 14 - nx test scope-manager --coverage=false
• Node 14 - nx test parser --coverage=false
• Node 18 - nx test eslint-plugin-internal
• Node 18 - nx test ast-spec
• Node 14 - nx test type-utils --coverage=false
• Node 14 - nx run types:build
• nx run types:build
• Node 14 - nx test utils --coverage=false
• Node 14 - nx test eslint-plugin-internal --coverage=false
• Node 14 - nx test ast-spec --coverage=false
• Node 14 - nx test repo-tools --coverage=false
• Node 14 - nx test visitor-keys --coverage=false
• Node 14 - nx test rule-schema-to-typescript-types --coverage=false
• nx run-many --target=build --parallel --exclude=website --exclude=website-eslint

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[JoshuaKGoldberg]

For future reviewing reference...

[...document.querySelectorAll(".file-header:has(.rgh-seen--11765709499)")]
    .filter(e => e.textContent.includes("packages/eslint-plugin/tests/rules/") && e.textContent.includes(".test.ts"))
    .forEach(e => e.querySelector("form label").click())

[JoshuaKGoldberg]

🎊

[JoshuaKGoldberg]

[Docs] Can you include a tracking GH issue?

[JoshuaKGoldberg]

[Docs] Can you also file a delection tracking issue & link to it here? I'm guessing it'll be a v7 breaking change.

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[bradzacher]

re-requesting reviews because I've made this a breaking change.
This completely removes RuleTester from /utils now - will update the blog post to point users at the new package

[armano2]

is there a reason why we are not preserving loine/col/endCol ?

its a good practice to add those to validate if error message is reported in correct place

[bradzacher]

because I couldn't be bothered remapping each one before and after the prettier format.
it already took long enough to extract and convert things away from the utility as it is.

soon™️ I'll implement snapshot testing in the fork which will snapshot an error underline and will make the line/col assertions unnecessary cruft anyways.

[JoshuaKGoldberg]