test: use builtins for type annotations instead of List / Optional

tests/procs.py

@@ -1,19 +1,19 @@
 import subprocess
 from pathlib import Path
-from typing import IO, Any, List, Optional, Union
+from typing import IO, Any
 
-_FILE = Union[None, int, IO[Any]]
-_DIR = Union[None, Path, str]
+_FILE = None | int | IO[Any]
+_DIR = None | Path | str
 
 
 def run(
-    cmd: List[str],
+    cmd: list[str],
     text: bool = True,
     check: bool = True,
     cwd: _DIR = None,
     stderr: _FILE = None,
     stdout: _FILE = None,
-    env: Optional[dict[str, str]] = None,
+    env: dict[str, str] | None = None,
 ) -> subprocess.CompletedProcess:
     if cwd is not None:
         print(f"cd {cwd}")