tests(test_builder) Remove tmux 3.2a skip marker

Remove skip marker from test_start_directory_sets_session_path.
This test uses a format introduced in tmux 3.2a, which is now the
minimum version.

Author: tony

tests/workspace/test_builder.py

@@ -598,10 +598,6 @@ def f(path: str, p: Pane) -> bool:
             assert retry_until(f_)
 
 
-@pytest.mark.skipif(
-    has_lt_version("3.2a"),
-    reason="needs format introduced in tmux >= 3.2a",
-)
 def test_start_directory_sets_session_path(server: Server) -> None:
     """Test start_directory setting path in session_path."""
     workspace = ConfigReader._from_file(