Log message:
python/wheel.mk: simplify a lot, and switch to 'installer' for installation

This follows the recommended bootstrap method (flit_core, build, installer).

However, installer installs different files than pip, so update PLISTs
for all packages using wheel.mk and bump their PKGREVISIONs.

Log message:
py-editables: update to 0.5.

Release 0.5

    Fix a bug that broke importlib.invalidate_caches

Release 0.4

    Add a new add_to_subpackage method.
    Add type annotations.
    Internal admin: Switch to nox for automation
    Internal admin: Switch to ruff for linting
    Internal admin: Switch from setuptools to flit_core

Log message:
py-editables: added version 0.3

This library supports the building of wheels which, when installed, will expose
packages in a local directory on sys.path in "editable mode". In other \ 
words,
changes to the package source will be reflected in the package visible to
Python, without needing a reinstall.