Skip pip option values in registry date updater

[hiSandog]

Summary

• teach the registry date updater to skip pip install options that consume a following value
• keep package-date detection working for commands such as python -m pip install --index-url URL --trusted-host HOST py4csr
• add regression coverage for this parser case

Validation

• python3 -c "import importlib.util; from pathlib import Path; path=Path('.github/scripts/tests/test_update_registry_dates.py'); spec=importlib.util.spec_from_file_location('test_update_registry_dates', path); mod=importlib.util.module_from_spec(spec); spec.loader.exec_module(mod); tests=[name for name in dir(mod) if name.startswith('test_')]; [getattr(mod, name)() for name in tests]; print(f'ran {len(tests)} update_registry_dates tests')"
• python3 -m py_compile .github/scripts/update_registry_dates.py .github/scripts/tests/test_update_registry_dates.py
• git diff --check

Note: pytest is not installed in this local environment, so the pytest-style tests were executed directly as plain Python test functions.