[#28187] Add gradle targets to execute python tests with prism.

[lostluck]

• Copies the Flink equivalent tasks.
• Validated that the validatesRunnerTests build and pass (assuming you have all the Python set up)
  • Sickbayed / skipped the 3 remaining failing tests around CustomWindows and Coders for now.
• Added target for iterating against trigger semantics. Will eventually be part of the PreCommit.

This is a required task before adding a Precommit action for running the Python suites against prism. That work will be in a separate PR.

A part of #28187.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.84%. Comparing base (301286f) to head (201bdb9).
Report is 34 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##             master   #32637   +/-   ##
=========================================
  Coverage     58.84%   58.84%           
  Complexity     3091     3091           
=========================================
  Files          1130     1130           
  Lines        174044   174048    +4     
  Branches       3320     3312    -8     
=========================================
+ Hits         102414   102422    +8     
- Misses        68293    68295    +2     
+ Partials       3337     3331    -6     

Flag	Coverage Δ
python	81.41% <ø> (+<0.01%)	⬆️

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