Spec-classes

This is a minor patch release that properly fixes the bug addressed by v1.2.5. That is: a race-condition during copying when used in a multi-threaded context. This would have manifested as a KeyError: <class 'module'> during copying.

The previous solution didn't work because we inadvertently constructed multiple locks per process, which defeats the point of the lock.

This is a minor patch release that fixes a race-condition during copying when used in a multi-threaded context. This would have manifested as a `KeyError: <class 'module'>` during copying.

(Same as 1.2.3).

Identical to 1.2.2. Attempting to fix artifact issue on PyPI.

This is a patch release that fixes an issue where passing dictionaries for dictionary types is conflated with constructor arguments.

This is a minor patch release that adds a few minor feature extensions and fixes a few bugs. In particular:

- Added support for constructing nested spec-classes from a dictionary of arguments to pass to the nested spec-class constructor (e.g. `MyClass(nested={"attr": "value"})`.
- Added `*polymorphic` and `*constructor` cached attributes to `Attr`.
- Fixed dataclasses compatibility on non-bootstrapped spec-classes (lookups on `__dataclass_fields__` will now properly trigger bootstrapping and return the appropriate spec-class attributes).
- Fixed type-checks involving `Literal` annotations.