Pytaglib

This is the first release of pytaglib that targets [Taglib 2.0](https://github.com/taglib/taglib/releases/tag/v2.0),
a major upgrade of the underlying C++ Taglib library.

- [!125](https://github.com/supermihi/pytaglib/pull/125): stop building wheels for out-of-support Python versions 3.6 and 3.7
- [!123](https://github.com/supermihi/pytaglib/pull/123): upgrade to Taglib 2.0

Thanks to [Urs Fleisch](https://github.com/ufleisch) for help
- [135](https://github.com/supermihi/pytaglib/pull/135): natively build arm64 wheels on macos-14 runner

- [!118](https://github.com/supermihi/pytaglib/pull/118): update Taglib version for binary wheels to 1.13.1
- [!117](https://github.com/supermihi/pytaglib/pull/117): modernize packaging / tooling
- [!116](https://github.com/supermihi/pytaglib/pull/116): fix Python 3.12 build

- update Taglib version for binary wheels to 1.13
- improve `build_taglib.py` helper script (now supports all platforms)
- add `taglib_version()` to the `taglib` module
- bundle native Taglib whith binary wheels (even on Unix). This enables to use the latest Taglib version (distributions often ship outdated
versions) and removes native dependencies.
- use [cibuildwheel](https://cibuildwheel.readthedocs.io) to provide binary wheels for a multitude of platform / Python version combinations
(fixes 101 105)
- allow using `File` as a context manager, optionally saving on exit
- new property `File.is_closed`
- fix 94: Accept `os.PathLike` in constructor

Breaking Changes:

- `File.path` is now a `Path` object

- fix 93: publish PyPI packages from GitLab workflow
- fix 92: build windows binary wheels from CI
- fix 89: remove Python 2 support
- fix 88: rename pyprinttags3 --> pyprinttags, ignore unsupported tags in the script

- fix 65: use tox for testing. Request re-cythonizing module with environment variable `PYTAGLIB_CYTHONIZE` instead of argument to `setup.py` now.
- fix 63: python2 tests did not pass
- fix 62: pyprinttags module did not work

- Fix published taglib.cpp