Revert "Remove StringArrayTypes type hint"

This reverts commit ce76152.

Author: weiji14

pygmt/_typing.py

@@ -2,7 +2,17 @@
 Type aliases for type hints.
 """
 
+import contextlib
+import importlib
+from collections.abc import Sequence
 from typing import Literal
 
+import numpy as np
+
 # Anchor codes
 AnchorCode = Literal["TL", "TC", "TR", "ML", "MC", "MR", "BL", "BC", "BR"]
+
+# String array types
+StringArrayTypes = Sequence[str] | np.ndarray
+with contextlib.suppress(ImportError):
+    StringArrayTypes |= importlib.import_module(name="pyarrow").StringArray