Add support for entrypoint-less scripts

[JeanChristopheMorinPerso]

Fixes #204

Add support for entrypoint-less scripts. For example, ruff ships an executable in the wheel's .data folder without declaring an entrypoint.

[JeanChristopheMorinPerso]

@czerouni can you give this a try please? This should fix #204.

[codecov]

Codecov Report

❌ Patch coverage is 92.85714% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.83%. Comparing base (64d3a93) to head (76a209a).
⚠️ Report is 6 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/rez_pip/rez.py	92.85%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #234      +/-   ##
==========================================
- Coverage   89.84%   89.83%   -0.02%     
==========================================
  Files          14       14              
  Lines        1064     1072       +8     
  Branches      206      210       +4     
==========================================
+ Hits          956      963       +7     
  Misses         70       70              
- Partials       38       39       +1     

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[czerouni]

Trying to test this, I must be doing something wrong. I checked out this project, then

$ git switch support_script_without_entrypoints
$ python -m venv venv
$ source venv/bin/activate
(venv) pip install .
(it installs this project)
(venv) which rez-pip2
/home/craigz/projects/rez-pip/venv/bin/rez-pip2
(venv) rez-pip2 ruff
rez_pip.rez.NoPythonFound: No package family named 'python' found

Any ideas?

Edit: I forgot that my default python is 3.12. I tested this in a different environment and it worked as expected. Ship it!