Update errorResponseBuilderContext type with ban property

[leonitousconforti]

According to the README: When the ban limit is exceeded the context field will have ban=true in the errorResponseBuilder. This just updates the types to reflect that. I have been using the field and it works as expected, just updating the types so I don't have to use a ts-ignore comment

Checklist

• run npm run test and npm run benchmark not needed?
• tests and/or benchmarks are included
• documentation is changed or added documentation is already correct
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[leonitousconforti]

Not entirely sure why all those tests are failing, but I don't understand how it could be from my change to the types

[Eomm]

It is due to this PR: fastify/light-my-request#248

We need to update the comparisons

[Uzlopak]

@Eomm
created a PR to fix the CI

#299

[Eomm]

can't update the branch tho

[Eomm]

@leonitousconforti could you add a test here https://github.com/fastify/fastify-rate-limit/blob/master/types/index.test-d.ts too?

[leonitousconforti]

Let me know what you think about the changes to the tests

[mcollina]

lgtm