[FR] add ability to remove provider via python admin sdk

[hardikns]

Is your feature request related to a problem? Please describe.
deleteProvider field for updateUser has been documented and implemented in other admin SDK like nodejs. Its missing in the python admin sdk

Describe the solution you'd like
Add the feature in the python admin sdk as well that will allow users to delete providers (like google.com, facebook.com) when email address changes for the user. Basically add delete_providers as input to update_user method in auth.

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[hardikns]

@hiranya911 - I have created a PR for the same. #579 pls have a look and see if you can accept it.

[hiranya911]

PR has been merged.