* Change PYBIND11_MODULE to use multi-phase init
Use slots to specify advanced init options (currently just Py_GIL_NOT_USED).
Adds a new function `initialize_multiphase_module_def` to module_, similar to the existing (unchanged) create_extension_module.
* Avoid dynamic allocation and non-trivial destruction
... by using an std::array for the slots.
* Oops, stray cut and paste character
* Remove assignment from placement new, change size fo slots array
* style: pre-commit fixes
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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
