Fix python-kasa library usage so every command works

[tommoyer]

Based on the documentation from the python-kasa library, we must create a new SmartPlug object for each async function instead of reusing the same SmartPlug object in each function

[codecov]

Codecov Report

Attention: Patch coverage is 10.00000% with 9 lines in your changes missing coverage. Please review.

Project coverage is 64.57%. Comparing base (931fe48) to head (d23c0ce).
Report is 24 commits behind head on main.

Files with missing lines	Patch %	Lines
src/maaspower/devices/kasa_device.py	10.00%	9 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #35      +/-   ##
==========================================
- Coverage   69.18%   64.57%   -4.62%     
==========================================
  Files          10       12       +2     
  Lines         370      463      +93     
==========================================
+ Hits          256      299      +43     
- Misses        114      164      +50     

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[gilesknap]

Thanks for this! There are a couple of minor errors in the CI.

You can run CI locally using tox -p after doing a pip install -e .'[]dev'

[gilesknap]

nice! merging.