chore: lint source code using Ruff

src/jcloud_docsgen/utils.py

@@ -16,11 +16,11 @@
 The utilities for jcloud_docsgen
 """
 
-import pathlib
-import os
 import errno
-from typing import Union
+import os
+import pathlib
 import types
+from typing import Union
 
 try:
     from warnings import deprecated
@@ -152,11 +152,7 @@ def _list_type_names(types: list[type]) -> list[str]:
 
 def assert_that_is_instance(
     obj: object,
-    class_or_tuple: Union[
-        type,
-        types.UnionType,
-        tuple[type, ...],
-    ],
+    class_or_tuple: type | types.UnionType | tuple[type, ...],
 ) -> None:
     if not isinstance(class_or_tuple, Union[type, types.UnionType, tuple]):
         raise TypeError(
@@ -185,7 +181,7 @@ def assert_that_is_instance(
         )
 
 
-def non_empty_str(value: Union[str, None]) -> Union[str, None]:
+def non_empty_str(value: str | None) -> str | None:
     """
     Returns the value or ``None``.
 
@@ -195,10 +191,10 @@ def non_empty_str(value: Union[str, None]) -> Union[str, None]:
                  of spaces, it is also considered empty.
 
     :param value: The value.
-    :type value: Union[str, None]
+    :type value: str | None
 
     :return: The value or ``None``.
-    :rtype: Union[str, None]
+    :rtype: str | None
     """
 
     if value is None: