[BEAM-5878] Add (failing) kwonly-argument test

[TheNeuralBit]

DoFnSignature and MethodWrapper don't properly handle kwonly arguments (some TODO(BEAM-5878) references in the codebase point to the paths that need to be updated).

GitHub Actions Tests Status (on master branch)

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[TheNeuralBit]

R: @lazylynx @tvalentyn

[codecov]

Codecov Report

Merging #17509 (6d398dc) into master (b3c99b0) will increase coverage by 0.00%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #17509   +/-   ##
=======================================
  Coverage   73.85%   73.85%           
=======================================
  Files         690      690           
  Lines       90843    90843           
=======================================
+ Hits        67093    67095    +2     
+ Misses      22537    22535    -2     
  Partials     1213     1213           

Flag	Coverage Δ
python	83.65% <ø> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ks/python/apache_beam/runners/worker/sdk_worker.py	88.90% <0.00%> (-0.16%)	⬇️
sdks/python/apache_beam/transforms/util.py	96.06% <0.00%> (-0.16%)	⬇️
...eam/runners/portability/fn_api_runner/execution.py	93.08% <0.00%> (+0.64%)	⬆️

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