Fix TypeScript linter error causing CI failure

[Martin Jambon]

See https://app.circleci.com/pipelines/github/ahrefs/atd/266/workflows/e4071167-ef8b-44e4-8a97-5f617d7926d1/jobs/502

npm run lint

> lint
> tslint --project tsconfig.json && eslint *.ts


/home/opam/atd/atdts/test/ts-tests/everything.ts
  12:1  error  Do not use "@ts-nocheck" because it alters compilation errors  @typescript-eslint/ban-ts-comment

✖ 1 problem (1 error, 0 warnings)