[Rust] Release 0.49.7

Added

• CanonicalizeOptions::with_retriever to fetch external resources absent from the registry.
• CanonicalizeOptions::with_base_uri to resolve relative references in the root schema.
• Canonicalization of a oneOf whose branches name disjoint targets, which degrades to a union.
• Canonicalization of a vacuous patternProperties entry beside schema-valued additionalProperties, where matching keys escape its value constraint.
• Canonicalization of a Draft 4 closed pattern map with a reference nested under a property.
• Canonicalization of Draft 4 closed pattern maps that meet through an applicator.
• The complement of a reference back to a target already being negated, which stays symbolic instead of declining.
• CanonicalSchema::definition resolving # to the document the handle was read against.

Performance

• Up to 150x faster canonicalization of not over a union of many branches.
• 2% faster emission of canonical schemas, which no longer formats copied string values.
• 5% faster emission of canonical schemas, which no longer formats object keys while copying them.
• Up to 12% faster canonicalization of schemas that repeatedly intersect the same branches.
• 13% faster canonicalization of a non-dynamic OpenAPI document, which no longer scans every schema object for dynamic references.
• Faster canonicalization of schemas with local $defs references, which avoid decoding unescaped definition names.
• 23% faster canonicalization of an object whose keys a finite property-name set spells.
• 3% faster intersection of schemas where one side constrains nothing.
• Up to 31x faster canonicalization of a oneOf whose many branches overlap.
• Up to 14x faster canonicalization of a union whose object branches share no values.
• 7% faster canonicalization of schemas that reach the same pair of nodes repeatedly.
• 5% faster canonicalization of objects, whose property maps no longer reach the allocator.
• Up to 8% faster canonicalization of schemas that reach true and false subschemas repeatedly.
• 2% faster canonicalization of schemas that assert known string formats.

Fixed

• CanonicalSchema::definition and CanonicalSchema::definitions handing out a target that names the document root without that document, where # points at the target instead.
• An items tail beyond an array's length ceiling surviving canonicalization, where it governs no element.
• CanonicalSchema::to_json_schema leaving the document root out of a node emitted below it, where # points at that node instead.