Improve cleanup type definition

[galkin]

Description

Right pull improves type definition for cleanup method.

Before:

import firebase_function_test from 'firebase-functions-test';
const ffTest = firebase_function_test();
// eslint-disable-next-line @typescript-eslint/no-unsafe-call
ffTest.cleanup();

After

import firebase_function_test from 'firebase-functions-test';
const ffTest = firebase_function_test();
ffTest.cleanup();

[galkin]

@TheIronDev, @taeold, @blidd-google could you approve this tiny change?

[galkin]

@TheIronDev, @taeold, @blidd-google friendly reminder

[TheIronDev]

@galkin Thank you for contributing!!

(and apologies for the delay.)

I just ran the CI test workflows, and there is a format issue blocking submission.

Would you be able to run npm run format:fix ?

Otherwise the code LGTM!

[galkin]

@TheIronDev done

[TheIronDev]

Your update will get included in the next release (date is tbd.)

Thank you for contributing (and my apologies on the delays in the review!)