Fix sdist build under setuptools >= 82 (pkg_resources removed) by sethc555 · Pull Request #598 · html5lib/html5lib-python

…>=82)

setuptools 82.0.0 (2026-02-08) removed pkg_resources, so building this
project's sdist in a default isolated build environment fails with
ModuleNotFoundError: No module named 'pkg_resources'.

Remove the setuptools<18.5/_markerlib compatibility shims that were the only pkg_resources users; they were dead code on any modern setuptools.

Verified: the patched sdist builds a wheel with setuptools 82 in a
clean python:3.12 container; the unpatched one does not.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>