Clean mixin execute

[janiversen]

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[janiversen]

@alexrudd2 this should solve the mypy problem with mixin.py

[alexrudd2]

@alexrudd2 this should solve the mypy problem with mixin.py

Yes, it solves the problem with execute(). Thanks!

I believe it should now be possible to solve the others, which are all similar. mypy does not know that ReadCoilsResponse is a subclass of ModbusResponse. Probably it should be e.g. Type[ModbusResponse] which is a type, instead of ModbusResponse, an an instance of a class. I will try to do something like this.
pymodbus/client/mixin.py:69: error: Incompatible return value type (got "ModbusResponse", expected "ReadCoilsResponse") [return-value]

[janiversen]

Sounds correct, but to be honest for me mypy is "try and fail" 👎 but it is nice once it is done.

I will not be touching mixin.py for a while.