Support pymongo 4.X

[opoplawski]

Looks like motor should now support pymongo 4.X with the release of 3.0.0. It would be nice if pysaml2 could support it so we could update pymongo in Fedora. See also #843

[c00kiemon5ter]

Fixed by 37d92b3

[kyrias]

Any idea of when a new release with the fix will be made? The commit that fixes the API usage sadly doesn't apply on the latest release.

[c00kiemon5ter]

Hello, I will be making new releases within this week.