Use TypeAlias where possible for type aliases (#7630)

stubs/PyYAML/yaml/constructor.pyi

@@ -1,9 +1,10 @@
 from typing import Any, Pattern
+from typing_extensions import TypeAlias
 
 from yaml.error import MarkedYAMLError
 from yaml.nodes import ScalarNode
 
-_Scalar = str | int | float | bool | None
+_Scalar: TypeAlias = str | int | float | bool | None
 
 class ConstructorError(MarkedYAMLError): ...
 

stubs/PyYAML/yaml/cyaml.pyi

@@ -1,6 +1,7 @@
 from _typeshed import SupportsRead
 from collections.abc import Mapping, Sequence
 from typing import IO, Any
+from typing_extensions import TypeAlias
 
 from ._yaml import CEmitter, CParser
 from .constructor import BaseConstructor, FullConstructor, SafeConstructor, UnsafeConstructor
@@ -9,7 +10,7 @@ from .resolver import BaseResolver, Resolver
 
 __all__ = ["CBaseLoader", "CSafeLoader", "CFullLoader", "CUnsafeLoader", "CLoader", "CBaseDumper", "CSafeDumper", "CDumper"]
 
-_Readable = SupportsRead[str | bytes]
+_Readable: TypeAlias = SupportsRead[str | bytes]
 
 class CBaseLoader(CParser, BaseConstructor, BaseResolver):
     def __init__(self, stream: str | bytes | _Readable) -> None: ...

stubs/PyYAML/yaml/reader.pyi

@@ -1,9 +1,10 @@
 from _typeshed import SupportsRead
 from typing import Any
+from typing_extensions import TypeAlias
 
 from yaml.error import YAMLError
 
-_ReadStream = str | bytes | SupportsRead[str] | SupportsRead[bytes]
+_ReadStream: TypeAlias = str | bytes | SupportsRead[str] | SupportsRead[bytes]
 
 class ReaderError(YAMLError):
     name: Any