Describe the issue:

NEP-50 nicely promotes, e.g., python floats to whatever float dtype an array has. However, for outer functions, this is not followed.

Reproduce the code example:

import numpy as np
a = np.arange(10.0, dtype="f4").reshape(5, 2)
np.add(1.0, a).dtype
# dtype('float32')
np.add.outer(1.0, a).dtype
# dtype('float64')

Error message:

Python and NumPy Versions:

2.4.6
3.14.6 (main, Jun 10 2026, 18:54:31) [GCC 15.2.0]

Runtime Environment:

Not relevant.

How does this issue affect you or how did you find it:

Found while reviewing #32040.