[Rust] Release 0.51.0

Added

• ValidationOptions::with_vocabulary and the vocabularies attribute on jsonschema::validator, declaring support for a vocabulary this crate does not implement.
• The --vocabulary flag of jsonschema validate.

Changed

• Vocabulary gained the FormatAssertion variant, which its Draft 2020-12 URI parses to instead of Vocabulary::Custom, and is marked non_exhaustive.

Fixed

• The uniqueItems length ceiling not reading an items or contains schema written as a $ref.
• The Draft 2020-12 Format-Assertion vocabulary read as an annotation, so a meta-schema requiring it accepted values its format rejects.
• An unrecognized format accepted under a meta-schema requiring the Format-Assertion vocabulary (it should be rejected).
• A meta-schema requiring a vocabulary this crate does not implement accepted (it should be rejected).
• The Draft 2019-09 Format vocabulary declared true read as an annotation, so a meta-schema requiring it accepted values its format rejects.
• The bundled https://json-schema.org/draft/2020-12/meta/format-assertion meta-schema not declaring its vocabulary, so a schema written against it annotated format instead of asserting it.
• A meta-schema without $id keeping its $vocabulary unread, so a schema written against it got every Draft 2020-12 vocabulary.
• A schema naming a bundled vocabulary meta-schema as its $schema rejected as an unknown meta-schema (it should build).
• The regex format reading the Rust regex dialect (it should read the ECMA-262 dialect in Unicode mode).
• The uri-template format rejecting an apostrophe in a literal (it should accept it, per RFC 6570 errata 6937).
• The duration format accepting weeks combined with a time part, such as P1WT1H (it should reject it).
• Stack overflow compiling unevaluatedProperties or unevaluatedItems beside a $ref that cycles back to the node, written as #, through its $id, or through a chain of definitions.

Performance

• Building unevaluatedProperties or unevaluatedItems over a deep allOf or $ref chain costs its depth instead of its square.