fix(py_pex_binary): exclude hermetic python toolchain files to prevent AmbiguousDistributionError

[xangcastle]

Problem

When building a py_pex_binary from a py_binary that uses a hermetic Python toolchain (e.g., from rules_python), the build fails with:

pex.dist_metadata.AmbiguousDistributionError: Found more than one distribution inside external/python3_9_x86_64-unknown-linux-gnu/lib/python3.9/site-packages/:
pip-23.2.1.dist-info/METADATA
setuptools-68.2.2.dist-info/METADATA

This happens because the hermetic Python interpreter includes pip and setuptools in its site-packages, and py_pex_binary was incorrectly including these as dependencies. When Distribution.load() is called on the site-packages directory, it finds multiple .dist-info directories and raises an error.

Solution

Exclude hermetic Python toolchain files from being processed as PEX dependencies:

1. Added exclusion pattern for the hermetic interpreter repository:

   • Pattern: python_interpreters+ (matches repos like aspect_rules_py++python_interpreters+python_3_11_aarch64_apple_darwin)

2. Added specific file exclusions for internal toolchain files:

   • _distutils_hack - Part of the interpreter's distutils shim
   • distutils-precedence.pth - Interpreter configuration file

Changes

• py/private/py_pex_binary.bzl: Added exclusion patterns and specific file filters
• py/tests/py-pex-binary/BUILD.bazel: Updated test to use hermetic Python 3.11 toolchain to validate the fix

Testing

bazel test //py/tests/py-pex-binary:test__print_modules_pex
//py/tests/py-pex-binary:test__print_modules_pex PASSED

[jbedard]

Don't we need the ~ version as well?

[jbedard]

Also I think if CI passed then either this line is not needed or it is not being tested...

[jbedard]

What is this?

[jbedard]

Can that be a separate test? This is replacing an old test, not "also" testing something...