GH-42018: Add numpy.StringDType support #54903

Job	Run time
AMD64 Windows 2022 Python 3.13	4m 40s
AMD64 Conda Python 3.10 Sphinx & Numpydoc	14m 44s
AMD64 macOS 15-intel Python 3	9m 52s
ARM64 macOS 14 Python 3	5m 12s
AMD64 Conda Python 3.11 Without Pandas	3m 58s
AMD64 Conda Python 3.12 without NumPy	3m 55s
AMD64 Conda Python 3.10 Pandas 1.3.4	9m 24s
AMD64 Conda Python 3.13 Pandas latest	3m 30s
	55m 15s

Provide feedback