[Rust] Release 0.54.0

Added

• backend = SerdeJson on #[jsonschema::validator], generating a validator that reads serde_json::Value.
• PreparedDocument::unsatisfiable_pointers, listing every subschema no value satisfies.

Changed

• Canonicalization of unevaluated* beside dependentSchemas or if/then/else, which kept the document Raw.
• Canonicalization of not over patternProperties, which kept the document Raw.

Performance

• validate and iter_errors check each assertion keyword with the is_valid path and build an error only for a failing one.
• evaluate holds its output tree in one allocation instead of one per node.
• A pattern of ^\S*$ scans bytes instead of decoding every character.
• validate on properties beside a two-name required confirms both names in the pass that checks the properties, instead of looking each up first.
• A string enum compares an option's length and first and last eight bytes before its full text.
• A JSON Pointer segment is scanned for ~ and / eight bytes at a time before it is copied.
• Canonicalization cloning leaves per intersection and the definition map per settled target.

Fixed

• type: array with items and minItems/maxItems checking the built-in length bound even when a custom keyword overrides minItems or maxItems, so the bound was evaluated twice.
• A custom keyword overriding type, required or maxLength not replacing the built-in check for that keyword.
• A custom keyword overriding items, minLength, properties or additionalProperties leaving its sibling keywords unchecked.
• #[jsonschema::validator] generated code that named serde_json directly, so it needed the consumer crate to depend on serde_json too.
• Canonicalization of not over an object with properties, patternProperties and additionalProperties, which applied additionalProperties to the keys listed in properties.