types(test_builder) Fix typing issues

tests/workspace/test_builder.py:721: error: Argument "start" to "enumerate" has incompatible type "Union[str, int, None]"; expected "int"  [arg-type]
tests/workspace/test_builder.py:722: error: Argument 1 to "int" has incompatible type "Optional[str]"; expected "Union[str, Buffer, SupportsInt, SupportsIndex, SupportsTrunc]"  [arg-type]
tests/workspace/test_builder.py:726: error: Unsupported operand types for - ("int" and "str")  [operator]
tests/workspace/test_builder.py:726: error: Unsupported operand types for - ("int" and "None")  [operator]
tests/workspace/test_builder.py:726: note: Right operand is of type "Union[str, int, None]

Author: tony

tests/workspace/test_builder.py

@@ -718,7 +718,10 @@ def test_pane_order(session: Session) -> None:
 
     for w in session.windows:
         pane_base_index = w.show_window_option("pane-base-index", g=True)
+        assert pane_base_index is not None
+        pane_base_index = int(pane_base_index)
         for p_index, p in enumerate(w.panes, start=pane_base_index):
+            assert p.index is not None
             assert int(p_index) == int(p.index)
 
             # pane-base-index start at base-index, pane_paths always start