jsonschema implementation uses functions that no longer exists

[Erik Olof Gunnar Andersson]

When reviewing the designate schema code I noticed that there are a lot of deprecated warnings, and at least one function no longer exists in the version of jsonschema that we use.

[Erik Olof Gunnar Andersson (eandersson)]

Example of function that we use that no longer exists
https://github.com/python-jsonschema/jsonschema/commit/00031cb043763842266877923552e40f0c8f36b5
https://github.com/openstack/designate/blob/29097ed55953964557f28e75858bd211ce1c7bca/designate/schema/_validators.py#L44

Deprecated warnings
2023-08-17 17:12:30.641881 | ubuntu-jammy | /home/zuul/src/opendev.org/openstack/designate/designate/schema/format.py:51: DeprecationWarning: Accessing jsonschema.draft3_format_checker is deprecated and will be removed in a future release. Instead, use the FORMAT_CHECKER attribute on the corresponding Validator.
2023-08-17 17:12:30.641945 | ubuntu-jammy | draft3_format_checker = jsonschema.draft3_format_checker
2023-08-17 17:12:30.649672 | ubuntu-jammy | /home/zuul/src/opendev.org/openstack/designate/designate/schema/format.py:52: DeprecationWarning: Accessing jsonschema.draft4_format_checker is deprecated and will be removed in a future release. Instead, use the FORMAT_CHECKER attribute on the corresponding Validator.
2023-08-17 17:12:30.649729 | ubuntu-jammy | draft4_format_checker = jsonschema.draft4_format_checker

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/designate/+/891927
Committed: https://opendev.org/openstack/designate/commit/9d115c88a1d1e5e1429a4fa913209e4c7bb3531a
Submitter: "Zuul (22348)"
Branch: master

commit 9d115c88a1d1e5e1429a4fa913209e4c7bb3531a
Author: Erik Olof Gunnar Andersson <email address hidden>
Date: Sat Aug 19 21:34:55 2023 +0200

    Simplify schema implementation

    Removes all unused components of the schema code and
    simplified the schema class.

    Closes-Bug: #2031922
    Change-Id: Ia5e4a8760161424851eda22051385695ec2c7a9b

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/designate 17.0.0.0rc1 release candidate.