fixup

copier/template.py

@@ -9,7 +9,7 @@
 from functools import cached_property
 from pathlib import Path
 from shutil import rmtree
-from typing import Any, Literal, Mapping, Sequence
+from typing import Any, Literal, Mapping, Sequence, Union
 from warnings import warn
 
 import dunamai
@@ -153,7 +153,7 @@ class Task:
             Additional environment variables to set while executing the command.
     """
 
-    cmd: str | Sequence[str]
+    cmd: Union[str, Sequence[str]]
     extra_env: Env = field(default_factory=dict)