Update Mapping type to match new mypy

[sobolevn]

Hi!

I am working on a new feature in mypy and it identified a problem in your code.
Mapping[str, object] cannot be unpacked into priority: int = 0, lifetime: int = 60, lastseen: Optional[str] = None,, but Mapping[str, Any] can be.

Link: python/mypy#11151

[nolar]

Thanks for doing such checks pro-actively (it is an interesting idea!) and for sending this PR.

Please ignore the errors with DeprecationWarning: The loop argument is deprecated … — I am fixing them right now in a separate PR (#828). I will merge this PR as soon as I fix those asyncio issues (maybe a rebase will be needed).

[sobolevn]

Thanks a lot for the quick fix! 🤝