Use PEP 604 syntax wherever possible (#7493)

stdlib/dis.pyi

@@ -2,7 +2,7 @@ import sys
 import types
 from _typeshed import Self
 from opcode import *  # `dis` re-exports it as a part of public API
-from typing import IO, Any, Callable, Iterator, NamedTuple, Union
+from typing import IO, Any, Callable, Iterator, NamedTuple
 
 __all__ = [
     "code_info",
@@ -34,8 +34,8 @@ __all__ = [
 
 # Strictly this should not have to include Callable, but mypy doesn't use FunctionType
 # for functions (python/mypy#3171)
-_HaveCodeType = Union[types.MethodType, types.FunctionType, types.CodeType, type, Callable[..., Any]]
-_HaveCodeOrStringType = Union[_HaveCodeType, str, bytes]
+_HaveCodeType = types.MethodType | types.FunctionType | types.CodeType | type | Callable[..., Any]
+_HaveCodeOrStringType = _HaveCodeType | str | bytes
 
 class Instruction(NamedTuple):
     opname: str