Upgrading schemars 0.9 to 1

Removes the deprecated gen module.

Removes the include_type_name setting that added the "x-rust-type" property to generated schemas.

Renames JsonSchema::always_inline_schema() to inline_schema().

Removes the optional enumset1/enumset dependency because its JsonSchema impl did not match EnumSet's default serialization format.

Removes the phone validation attribute to match the latest validator crate.

Renames SchemaSettings::visitors to SchemaSettings::transforms.

Renames SchemaSettings::with_visitor to SchemaSettings::with_transform.

Renames SchemaGenerator::visitors_mut to SchemaGenerator::transforms_mut.

Renames GenVisitor to GenTransform.

Renames Visitor::visit_schema to Transform::transform.

Renames visit::visit_schema to transform::transform_subschemas.

Requires GenTransform to implement Send but no longer requires Debug.

Schemas from draft2019_09, draft2020_12 and default settings now use $defs instead of definitions.

Removes JsonSchema::is_referenceable() and replaces it with JsonSchema::always_inline(), which returns the opposite value.

Renames optional dependency features to include their versions: chrono04, either1, smallvec1, url2, bytes1, rust_decimal1, enumset1, smol_str02, semver1.

Removes deprecated SchemaGenerator methods make_extensible, schema_for_any and schema_for_none.

Removes the schemars::Set and schemars::Map type aliases.

Removes visit_schema_object and visit_root_schema from the Visitor trait; visit_schema is unchanged.

Removes old optional dependency versions: indexmap, uuid08, arrayvec05 and bigdecimal03.

Removes the retain_examples field from SetSingleExample, which is now a unit struct.

Uses patternProperties on map schemas where appropriate, so BTreeMap and HashMap only implement JsonSchema when both K and V do.

Invalid with/serialize_with attributes now fail compilation instead of being silently ignored.

Reworks nullable schema generation for Option<T>; option_nullable and option_add_null_type are no longer used and AddNullable transform controls nullable output.

Changes SchemaSettings::meta_schema and definitions_path from String to Cow<'static, str> to ease const construction.

SchemaGenerator::take_definitions now takes an apply_transforms flag to apply the generator's current transforms to returned schemas.

Changes the example attribute value to an arbitrary expression instead of a string literal naming a function, making string-literal function paths a compile error.

Invalid attributes that were previously silently ignored, such as setting schema_with on structs, now cause compile errors.

Requires regex and contains validation attributes in list form #[validate(regex(path = ...))] instead of name/value form.

Replaces the visit module and Visitor trait with transform and Transform, renaming related items.

Default SchemaSettings now conform to JSON Schema draft 2020-12 instead of draft 7.

JsonSchema::schema_name() now returns Cow<'static, str> instead of String.

The SchemaGenerator.definitions field is now a serde_json::Map<String, Value>.

Removes the schema module; Schema is now at the crate root and all other module types are removed.

Removes the impl_json_schema feature flag; JsonSchema is now always implemented on Schema.

Redefines the Schema type as a thin wrapper around a serde_json::Value.

Macros and functions that returned RootSchema now return Schema.

Raises the minimum supported Rust version to 1.74.

Raises the minimum supported Rust version (MSRV) to 1.70.

Raises the minimum supported Rust version (MSRV) to 1.65.

Deprecates GenTransform::as_any, to be removed before schemars 1.0 becomes stable.

Replaces the schemars::gen module with schemars::generate because gen is a reserved keyword in Rust 2024; schemars::gen remains but is deprecated.