Release v2.4.2

Fixed

• The yclept command no longer crashes on Python 3.14. config-help declared its --i and --exit-at-end flags with type=bool alongside action=BooleanOptionalAction; that keyword was deprecated in Python 3.12 and removed in 3.14, and because the whole argument parser is built before any subcommand runs, every yclept subcommand — make-doc and check-spec included — failed at startup with a TypeError. The flags parse exactly as before. The library API was unaffected, which is why the test suite passed on 3.14 all along: it called functions directly and never ran the CLI. A test now builds the parser in a subprocess, and CI covers Python 3.14