Firebase Auth testing mode to disable too many Auth requests for passwordless email implementation

## What feature would you like to see?

Implementing passwordless email authentication, deeplinking features or working on a bug is difficult because after only a few (5?) login attempts firebase is blocking the email for a certain time.

It seems this kind of limitation is not listed here: https://firebase.google.com/docs/auth/limits

Google "firebase auth too many requests" show a lot of result where develops are struggling with this issue.

## How would you use it?

It would be nice to be able to work on these complex integrations without needing to be forced to take a long coffee break every after every few attempts to get the code working properly