inspect.type_info crashes on mixed-type Literals #1018

`msgspec.inspect.type_info` crashes with `TypeError` when called on a `Literal` type that mixes value types (e.g. `Literal[1, None]` or `Literal[True, "yes"]`).

Reproduction

import msgspec.inspect as mi
from typing import Literal

mi.type_info(Literal[1, None])
# TypeError: '<' not supported between instances of 'NoneType' and 'int'

mi.type_info(Literal[True, "yes"])
# TypeError: '<' not supported between instances of 'str' and 'bool'

Cause

`inspect.py:888` does `LiteralType(tuple(sorted(args)))` which calls `sorted()` on the Literal args. Python 3 does not allow comparison between different types, so mixed-type tuples like `(1, None)` or `(True, "yes")` raise `TypeError`.

Additionally, `LiteralType.values` type annotation (`Union[Tuple[bool, ...], Tuple[str, ...], Tuple[int, ...]]`) does not cover mixed-type tuples.

Suggested fix

1. Replace `sorted(args)` with a type-aware sort (e.g. `sorted(args, key=lambda x: (type(x).name, x))`) or skip sorting for mixed types.
2. Widen `LiteralType.values` to `Tuple[Union[bool, str, int, None], ...]` or similar.
3. Add tests for `type_info(Literal[True])`, `type_info(Literal[True, "yes"])`, `type_info(Literal[1, None])`.

This is a pre-existing issue (not introduced by #1004), but #1004 makes it more likely to encounter since it enables `Literal[True, ...]` combinations.