BUG: newbyteorder docs and typing don't agree on allowed types

[dstansby]

Describe the issue:

For numpy.dtype.newbyteorder, https://numpy.org/doc/stable/reference/generated/numpy.dtype.newbyteorder.html lists allowable arguments as:

• ‘S’ - swap dtype from current to opposite endian
• {‘<’, ‘little’} - little endian
• {‘>’, ‘big’} - big endian
• {‘=’, ‘native’} - native order
• {‘|’, ‘I’} - ignore (no change to byte order)

but the typing doesn't allow 'little', 'big', or 'native':

numpy/numpy/__init__.pyi

Line 639 in 67257a7

_ByteOrder = L["S", "<", ">", "=", "|", "L", "B", "N", "I"]

Either the docs should be updated to match the typing, or the typing updated to match the docs.

Reproduce the code example:

import numpy as np
a = np.array([1, 2, 3])
a.dtype.newbyteorder("little")

Error message:

No response

Python and NumPy Versions:

1.26.4
3.12.2 | packaged by conda-forge | (main, Feb 16 2024, 20:54:21) [Clang 16.0.6 ]

Runtime Environment:

No response

Context for the issue:

No response

[rgommers]

Agreed, looks like the set of accepted literals missed this by accident. Updating the type annotation in gh-26480.