ruff

ff376fc2 - [red-knot] Allow explicit specialization of generic classes (#17023)

[red-knot] Allow explicit specialization of generic classes (#17023) This PR lets you explicitly specialize a generic class using a subscript expression. It introduces three new Rust types for representing classes: - `NonGenericClass` - `GenericClass` (not specialized) - `GenericAlias` (specialized) and two enum wrappers: - `ClassType` (a non-generic class or generic alias, represents a class _type_ at runtime) - `ClassLiteralType` (a non-generic class or generic class, represents a class body in the AST) We also add internal support for specializing callables, in particular function literals. (That is, the internal `Type` representation now attaches an optional specialization to a function literal.) This is used in this PR for the methods of a generic class, but should also give us most of what we need for specializing generic _functions_ (which this PR does not yet tackle). --------- Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com> Co-authored-by: Carl Meyer <carl@astral.sh>