Remove circumventions for Python 3.13

[andy-maier]

The initial support for Python 3.13-beta.1 in PR #976 had to implement some circumventions for the issue that the "pyo3-ffi" package used by the "maturin" build backend does not yet support Python 3.13 (see PyO3/pyo3#4038 (comment)).

This ticket is to use a future version of pyo3 that supports Python 3.13, and to remove the circumventions:

• In requirements.txt, the pinning of jsonschema to <4.18.0
• In dev-requirements.txt, the pinning of safety to <3.0.0