www/py-w3lib: update to 2.4.1

Changelog highlights (1.21.0 -> 2.4.1):

• Python 3.8+ required (dropped 2.7/3.7 support)
• Removed dependency on six
• Build converted to pep517 (hatchling backend)
• New URL parsing behavior: canonicalize_url() no longer removes dot-segments

Port changes:

• DISTVERSION 2.4.1, drop PORTREVISION
• Convert USE_PYTHON distutils -> pep517
• RUN_DEPENDS: drop py-six; add BUILD_DEPENDS on py-hatchling
• Enable tests: USE_PYTHON += pytest (241 passed, 76 xfailed)

PR: 297778
Reported by: skreuzer