chore: update eslint-plugin-testing-library to v6

[ripecosta]

Description

Updates eslint-plugin-testing-library to v6. Disables the testing-library/no-manual-cleanup rule, which is now active by default on the testing-library/react config, because vitest doesn't expose global afferEach methods.

Note: The lint step in failing in CI for an unrelated reason, which is fixed in #1791.

Checklist

• [x] only relevant code is changed (make a diff before you submit the PR)
• [x] run tests npm run test
• [x] tests are included
• [x] commit message and code follows the Developer's Certification of Origin

[coveralls]

coverage: 97.073%. remained the same when pulling d151f48120242c5b2964247f902024da95f72032 on ripecosta:rc/eslint-testing-library into e068e5eae9e6860641b8869b82d705453a7f3ca1 on i18next:master.