migrate to pyproject.toml

[branchv]

This project currently fails to build with pip's pep 517 build isolation (because setup.py imports from iOSbackup, which imports NSKeyedUnArchiver and won't be available):

Example

$ python3.12 -m venv .venv
$ .venv/bin/pip install --no-binary=iosbackup iosbackup
Collecting iosbackup
  Using cached iOSbackup-0.9.925.tar.gz (25 kB)
  Installing build dependencies ... done
  Getting requirements to build wheel ... error
  error: subprocess-exited-with-error

  × Getting requirements to build wheel did not run successfully.
  │ exit code: 1
  ╰─> [22 lines of output]
      Traceback (most recent call last):
        File "/private/var/folders/1r/p5nhsx151fd7j63p9r1zz4kw0000gn/T/tmp.bvMiQnfu2C/.venv/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 353, in <module>
          main()
        File "/private/var/folders/1r/p5nhsx151fd7j63p9r1zz4kw0000gn/T/tmp.bvMiQnfu2C/.venv/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 335, in main
          json_out['return_val'] = hook(**hook_input['kwargs'])
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/private/var/folders/1r/p5nhsx151fd7j63p9r1zz4kw0000gn/T/tmp.bvMiQnfu2C/.venv/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 118, in get_requires_for_build_wheel
          return hook(config_settings)
                 ^^^^^^^^^^^^^^^^^^^^^
        File "/private/var/folders/1r/p5nhsx151fd7j63p9r1zz4kw0000gn/T/pip-build-env-mkpzx40y/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 325, in get_requires_for_build_wheel
          return self._get_build_requires(config_settings, requirements=['wheel'])
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/private/var/folders/1r/p5nhsx151fd7j63p9r1zz4kw0000gn/T/pip-build-env-mkpzx40y/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 295, in _get_build_requires
          self.run_setup()
        File "/private/var/folders/1r/p5nhsx151fd7j63p9r1zz4kw0000gn/T/pip-build-env-mkpzx40y/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 487, in run_setup
          super().run_setup(setup_script=setup_script)
        File "/private/var/folders/1r/p5nhsx151fd7j63p9r1zz4kw0000gn/T/pip-build-env-mkpzx40y/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 311, in run_setup
          exec(code, locals())
        File "<string>", line 2, in <module>
        File "/private/var/folders/1r/p5nhsx151fd7j63p9r1zz4kw0000gn/T/pip-install-0397t0sk/iosbackup_14ad6c74c36b446dbc2daa557b9e42ad/iOSbackup/__init__.py", line 18, in <module>
          import NSKeyedUnArchiver
      ModuleNotFoundError: No module named 'NSKeyedUnArchiver'
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
error: subprocess-exited-with-error

× Getting requirements to build wheel did not run successfully.
│ exit code: 1
╰─> See above for output.

note: This error originates from a subprocess, and is likely not a problem with pip.

This migrates to static metadata instead via pyproject.toml (the modern replacement for setup.py)

$ python3.12 -m venv .venv
$ .venv/bin/pip install .
# ...
Successfully installed NSKeyedUnArchiver-1.5 iOSbackup-0.9.925 pycryptodome-3.20.0