Change union syntax for compatibility with older Python

jedi_language_server/jedi_utils.py

@@ -9,7 +9,7 @@
 import threading
 from ast import PyCF_ONLY_AST
 from inspect import Parameter
-from typing import Any, Callable, Dict, Iterator, List, Optional, Tuple
+from typing import Any, Callable, Dict, Iterator, List, Optional, Tuple, Union
 
 import docstring_to_markdown
 import jedi.api.errors
@@ -424,7 +424,7 @@ def clean_completion_name(name: str, char_before_cursor: str) -> str:
 _PARAM_NAME_IGNORE = {"/", "*"}
 
 
-def get_snippet_signature(signature: Signature | BaseSignature) -> str:
+def get_snippet_signature(signature: Union[Signature, BaseSignature]) -> str:
     """Return the snippet signature."""
     params: List[ParamName] = signature.params
     if not params: