Allow None for HyperlinkedRelatedField.get_url(format=) parameter

[4c0n]

I have made things!

Hi! I ran into a false positive when running mypy in combination with this package.
Actually the format parameter can also be None in the get_url() method, it is passed to reverse() where the default value also is None. We've been using it like this in our application for a long time and it works fine like that.
Please see:
https://github.com/encode/django-rest-framework/blob/3.14.0/rest_framework/relations.py#L326
https://github.com/encode/django-rest-framework/blob/3.14.0/rest_framework/reverse.py#L32

Thanks in advance for your time and consideration.

Related issues

I didn't create an issue, should I?

[intgr]

Thanks!

I didn't create an issue, should I?

No need. Only for more complex changes that you think warrant prior discussion.