Bump extern/pybind11 from 96b943b to 522c59c

Bumps [extern/pybind11](https://github.com/pybind/pybind11) from `96b943b` to `522c59c`.
- [Release notes](https://github.com/pybind/pybind11/releases)
- [Commits](pybind/pybind11@96b943b...522c59c)

---
updated-dependencies:
- dependency-name: extern/pybind11
  dependency-type: direct:production
...

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