* Fix load_all() argument
* Remove Python 2 remnants
+ Replace Text with str
+ Replace alias "_Str" with str
+ Import from collections.abc and re where applicable
+ Remove Python 2 branches
* Fix PyYaml allowlist entries
+ Add yaml._yaml and move CParser and CEmitter there.
+ Add missing functions, classes, and arguments.
* Use relative imports in some modules.
* Add __all__ to yaml.cyaml.
* Remove unnecessary noqa markers.
Added / modified types for the following functions:
- `add_implicit_resolver(...)`
- `add_path_resolver(...)`
- `add_constructor(...)`
- `add_multi_constructor(...)`
- `add_representer(...)`
- `add_multi_representer(...)`
* Remove yaml.add_constructor from allowlist
* Use TypeVars and overloads
