* Add Python 3.10, 3.11, 3.12 to win32 job matrix.

* Quotes around Python version numbers (win32 job).

* tests/requirements.txt: no scipy for Python >= 3.10 under win32

* Try running `cmake --build . --target cpptest` on all platforms (`standard` job).

* Change Python version guard: PYTHON < 3.7 IS UNSUPPORTED.

* Replace or remove Python 3.6 jobs.

* Move appveyor to Python 3.8

* Change `[tool.pylint]` `master.py-version` from `3.6` to `3.8`

* Change `[tool.pylint]` `master.py-version` to `3.7`

* Remove `centos:7` job; Change almalinux:8 job to use Python 3.8

* Try 🐍 3.8 • ubuntu-20.04 • x64 without `-DCMAKE_CXX_FLAGS="-D_=1"`

* Update setup.cfg as suggested by @henryiii

* Try running `cmake --build . --target cpptest` on all platforms (`standard` job).

* Disable deadsnakes jobs entirely.

* Apply PR pybind#5179: Add Python 3.10, 3.11, 3.12 to win32 job matrix.

* Add back `-DCMAKE_CXX_FLAGS="-D_=1"` but do not install boost in that case.

* PY_VERSION_HEX < 3.7 cleanup pass: include/pybind11

* WITH_THREAD cleanup pass: include/pybind11

* Undo incorrect change.

* Revert "Disable deadsnakes jobs entirely."

This reverts commit bbcd008.

* WITH_THREAD cleanup pass: tests/

* Change Python version guard in pybind11/__init__.py: pybind11 does not support Python < 3.7.

* Misc cleanup pass

* chore: use future imports

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Update tests/test_numpy_array.py

* Update test_numpy_array.py

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>

```
ruff.....................................................................Failed
- hook id: ruff
- files were modified by this hook

Fixed 44 errors:
- tests/test_class_sh_basic.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_disowning.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_disowning_mi.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_factory_constructors.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_inheritance.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_mi_thunks.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_module_local.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_property.py:
    1 × I002 (missing-required-import)
- tests/test_class_sh_property_non_owning.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_shared_ptr_copy_move.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_trampoline_basic.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_trampoline_self_life_support.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_trampoline_shared_from_this.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_trampoline_shared_ptr_cpp_arg.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_trampoline_unique_ptr.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_unique_ptr_custom_deleter.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_unique_ptr_member.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_class_sh_virtual_py_cpp_mix.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_classh_mock.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_descr_src_loc.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_exc_namespace_visibility.py:
    1 × I002 (missing-required-import)
- tests/test_type_caster_odr_guard_1.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)
- tests/test_type_caster_odr_guard_2.py:
    1 × I001 (unsorted-imports)
    1 × I002 (missing-required-import)

Found 44 errors (44 fixed, 0 remaining).
```