Support for non async functions

[Benoss]

My codebase has a mix of sync and async functions and I would love to be able to use the same cache library for everything.
Any plan to add a non async version of the decorators and Locks?

[ecarrara]

I plan to add sync support in the future, but it is not my current focus - my current use case is fully asynchronous.

PRs are welcome.