* Use PyCode API

* style: pre-commit fixes

* Free locals

* Fix PY_VERSION_HEX check

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Ensures `std::default_delete<T>` is used to look up the deleter for a type instead of `delete` directly.

* Roundtrip through unique pointer with custom deleter.

Currently failing.

* Ensure the custom deleter is copied back to the unique pointer.

Feels like there's still a gap around the raw pointer flavour, but this at least
makes the unit test of the previous commit succeed.

* Add deleter roundtrip for const atyp.

Currently failing, custom deleter is lost.

* Fix storing deleter for const unique ptr.

Unit test from the previous commit passes.

* Remove SFINEA deleter assignment.

At the construction of the smart holder, it is either a del_fun, or a default constructed deleter, so this complexity is unnecessary.

* Clang format.

* Fixes for ci.

Clang 3.6 requires the extra constructors in the custom_deleter.

* fix(smart_holder): Loosen requirement on deleter to be default constructible.

And some other PR feedback.

* fix(smart_holder): Custom deleter in unit tests traces constructions.

* fix(smart_holder): Use pybind11_fail instead of assert.

* fix(smart_holder): Add unit tests for the default constructible deleter.

* fix(smart_holder): Use regex matching for deleter constructors in unit tests.

updates:
- [github.com/pre-commit/mirrors-clang-format: v17.0.3 → v17.0.4](pre-commit/mirrors-clang-format@v17.0.3...v17.0.4)
- [github.com/astral-sh/ruff-pre-commit: v0.1.2 → v0.1.4](astral-sh/ruff-pre-commit@v0.1.2...v0.1.4)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgk@google.com>