py-authheaders: updated to 0.16.2

Version 0.16.2
- Add checks for None results to avoid tracebacks
- Account for FWS in From (which is legal, apparently)
  (Thanks to Mark Sapiro for the report and the fix)
- Delete more setup.py cruft for non-supported Pythons

Version 0.16.1
- Clean up unnecessary escaping of semi-colons in test data (Dig artifacts)
  and adjust related code to resolve SyntaxWarning with Python 3.12
- Set python_requires >3.7 and clean up cruft in setup.py
- Use importlib.resources instead of importlib_resources

(adam)