Krb5

* Require Python 3.8 or newer (dropped 3.7)
* Added Python 3.13 wheel for macOS
* Added password management APIs
* [krb5_chpw_message](https://web.mit.edu/kerberos/krb5-latest/doc/appdev/refs/api/krb5_chpw_message.html)
* [krb5_set_password](https://web.mit.edu/kerberos/krb5-latest/doc/appdev/refs/api/krb5_set_password.html)
* [krb5_set_password_using_ccache](https://web.mit.edu/kerberos/krb5-latest/doc/appdev/refs/api/krb5_set_password_using_ccache.html)

* Fix up wheel package build to not include uneeded `python_krb5.h` file in the final `site-packages` install dir
* Added CCache APIs:
* [krb5_cc_get_config](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_cc_get_config.html)
* [krb5_cc_set_config](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_cc_set_config.html)
* Added Context APIs:
* [krb5_set_real_time](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_set_real_time.html)
* [krb5_timeofday](https://web.mit.edu/Kerberos/krb5-devel/doc/appdev/refs/api/krb5_timeofday.html)
* [krb5_us_timeofday](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_us_timeofday.html)
* MIT only
* [krb5_get_time_offsets](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_get_time_offsets.html)
* Added Credential APIs:
* [krb5_get_renewed_creds](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_get_renewed_creds.html)
* MIT only
* [krb5_get_etype_info](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_get_etype_info.html)
* [krb5_get_validated_creds](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_get_validated_creds.html)
* MIT 1.20+ only
* [krb5_marshal_credentials](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_marshal_credentials.html)
* [krb5_unmarshal_credentials](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_unmarshal_credentials.html)
* Added KeyBlock APIs:
* MIT only
* [krb5_c_string_to_key](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_c_string_to_key.html)
* Added Principal APIs:
* [krb5_build_principal]https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_build_principal.html)
* Added the following properties to the `Creds` object:
* `ticket_flags_raw` - Flags in the ticket as returned by the C API
* `ticket_flags` - Flags in the ticket converted to a known enum value
* Added the following properties to the `Principal` object:
* `realm` - The realm of the principal
* `components` - The list of name components.
* `type` - The name type of the principal.

* Added support for Cython 3.x.y when building the extension modules
* Added Python 3.12 wheel for macOS

* Added exception that is raised when `krb5.init_context()` failed
* Moved back to `setup.cfg` based setuptools project for compatibility with `pip` present on system distributions
* Added the following properties to the `Creds` object:
* `client` - A copy of the credential's client principal
* `server` - A copy of the credential's server principal
* `keyblock` - A copy of the credential's session encryption key info
* `times` - A copy of the credential's lifetime info including the auth time, star time, end time, and renewal time
* `ticket` - A copy of the credential's ticket data
* `second_ticket` - A copy of the credential's second ticket data (`DUPLICATE-SKEY` or `ENC-TKT-IN-SKEY`)
* Added CCache APIs:
* [krb5_cc_remove_cred](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_cc_remove_cred.html)
* [krb5_cc_retrieve_cred](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_cc_retrieve_cred.html)
* Added Keyblock APIs:
* [krb5_copy_keyblock](https://web.mit.edu/kerberos/krb5-devel/doc/appdev/refs/api/krb5_copy_keyblock.html)

* Added Python 3.11 wheel

* Require Python 3.7 or newer (dropped 3.6)
* Created PEP 517 compliant package
* Moved all setuptools configuration, except extension information, to `pyproject.toml`
* Will no longer include the cythonised `.c` files in the sdist making Cython a build requirement
* With PEP 517 this requirement will be automatically satisfied making this a non-breaking change for people using PEP 517 features