removed unused loop for asyncio-timeout

[mh7d]

I removed the parameter loop from asyncio-timeout call. This parameter ahs been removed in version 4 of asyncio-timeout and is now braking the installation using pip.

Furthermore is set fixed version for dependencies in setup.py so that in future new version of used libs does not break this package again.

[mtdcr]

Thank you for your patch submission!

Because pysml gets used as a library, it shouldn't pin specific versions (or partial versions for that matter), because its users (e.g. Home Assistant) may change more frequently than pysml and depend on newer versions of the same libraries, causing conflicts as time goes by.

If you want to document a working set of versions, you could add an additional requirements.txt file and I'd happily accept that in an updated PR.

Whereas install_requires requirements are minimal, requirements files often contain an exhaustive listing of pinned versions for the purpose of achieving repeatable installations of a complete environment.

(Source: https://packaging.python.org/en/latest/discussions/install-requires-vs-requirements/#requirements-files)

[mh7d]

I will remove the fixed version, but requirements.txt is not needed inside this lib, as this is normally used for the whole project.

Perhaps it is a good idea, to have a look, if the loop parameters can be removed entirely, as the pyserial-asycnio team is thinking about deprecating this parameter as well: pyserial/pyserial-asyncio#66