`deprecated` JSON Schema flags should be supported

[dhryniewicz]

My particular use-case is marking some enums as deprecated. Like in here:
json-schema-org/json-schema-spec#1386

But I'm sure there should be a more generic solution.
json-schema-org/json-schema-spec#737
https://json-schema.org/draft/2020-12/draft-bhutton-json-schema-validation-01#name-deprecated