CI's license check fails on the new dev dep because liccheck cannot read
the PEP 639 'License-Expression' field that pytest-recording uses. Add
the package to the manually-verified allowlist (MIT, confirmed via PyPI
classifier).
Also addresses greptile P2 review comments:
- Add 'anthropic-version' to the request-header filter list so live and
mock recordings produce structurally identical cassettes.
- Replace the indentation-sensitive regex in
'_strip_nondeterministic_headers' with a YAML parse-and-rewrite so the
helper keeps working if vcrpy ever changes its serialization style.
Co-authored-by: Mateo Wang <mateo-berri@users.noreply.github.com>
