Add shebang functionality to tests

[gunnarku]

Tests that contain if __name__ == "__main__": now have a shebang line and execute permission.

Why are these changes needed?

The main reason for these changes is increased developer productivity and shortening the validation cycle. This functionality enables executing tests directly from the shell. We use the shebang functionality and execute permissions. The end result looks like this:

$ ./test_cache.py
========================================== test session starts ==========================================
platform darwin -- Python 3.11.7, pytest-7.4.4, pluggy-1.4.0
....
collected 4 items

test_cache.py ....                                                                                [100%]

=========================================== 4 passed in 0.46s ===========================================

This is the blunt logic (there probably is a more elegant way to accomplish this ;-)) that I used to make the updates on macOS:

find . -name '*.py' | xargs grep -r __main__ -l | xargs sed -i.tmp '1 i\'$'\n''#!/usr/bin/env python3 -m pytest'$'\n'''
find . -name '*.py' | xargs grep -r __main__ -l | xargs sed -i.tmp '2 i\'$'\n'''$'\n'''
find . -name '*.py' | xargs grep -r __main__ -l | xargs chmod +x
find . -name '*.tmp' | xargs rm

Discussion points:

• Should all tests have the if __name__ == "__main__": part to make running them easier? Currently they don't, potential follow-up work here.
• If yes, should pre-commit hook check for it?

Related issue number

N/A

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• [ X] I've made sure all auto checks have passed.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 48.16%. Comparing base (8ec1c3e) to head (08560ae).

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1784       +/-   ##
===========================================
+ Coverage   37.05%   48.16%   +11.10%     
===========================================
  Files          62       62               
  Lines        6499     6499               
  Branches     1438     1561      +123     
===========================================
+ Hits         2408     3130      +722     
+ Misses       3898     3120      -778     
- Partials      193      249       +56     

Flag	Coverage Δ
unittests	48.08% <ø> (+11.03%)	⬆️

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[ekzhu]

What is a concrete benefit of making these test files executable other than we don't need to type python ?

[jackgerrits]

This is nifty, I like it!

[gunnarku]

What is a concrete benefit of making these test files executable other than we don't need to type python ?

@ekzhu : The main benefit derives from a simple empirical observation: if running test cases is easy, then contributors tend to run tests more often, add new test cases, and perceive that the validation system helps them to be more effective.

A secondary purpose is to enable those contributors who use Unix-based operating systems (or even WSL on Windows) to use the workflow they are used to.

[gunnarku]

This is nifty, I like it!

@jackgerrits : Thank you! Shebang for the win! ;-)