Allow declaration of external dependencies for YAML UDFs.

[robertwb]

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[robertwb]

R: @derrickaw
CC: @damccorm @rezarokni

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[derrickaw]

Suggested change

	external_provider = ExternalPythonProvider( #
	external_provider = ExternalPythonProvider(

[codecov]

Codecov Report

Attention: Patch coverage is 66.26506% with 28 lines in your changes missing coverage. Please review.

Project coverage is 56.35%. Comparing base (76b0df9) to head (a4b2912).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
sdks/python/apache_beam/yaml/yaml_provider.py	51.06%	23 Missing ⚠️
sdks/python/apache_beam/yaml/yaml_transform.py	60.00%	4 Missing ⚠️
...beam/runners/portability/expansion_service_main.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##             master   #34073   +/-   ##
=========================================
  Coverage     56.35%   56.35%           
  Complexity     3286     3286           
=========================================
  Files          1173     1173           
  Lines        179087   179178   +91     
  Branches       3398     3398           
=========================================
+ Hits         100928   100982   +54     
- Misses        74904    74941   +37     
  Partials       3255     3255           

Flag	Coverage Δ
python	81.29% <66.26%> (-0.03%)	⬇️

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[robertwb]

I went ahead and skipped the test in the flaky environment, as it seems environmental. The other tests are pre-existing (and I'm seeing them in other PRs).