TYP: Various typing fixes

[charris]

Backports of #29842, #29845, #29846, #29847.

commit fe3a74c
Author: Joren Hammudoglu jhammudoglu@gmail.com
Date: Wed Oct 1 03:56:24 2025 +0200

TYP: Fix incompatible defaults in ``polyfit``, ``histogram``, and ``histogramdd`` (#29847)

The default values weren't assignable to the types of the parameters.

commit 2342cb0
Author: Joren Hammudoglu jhammudoglu@gmail.com
Date: Wed Oct 1 03:54:37 2025 +0200

TYP: Fix signatures of ``linalg.matmul`` and ``linalg.outer`` (#29846)

This fixes several issues in np.linalg.outer (positional-only params, a misplaced out=... param, and an orphanced -> _ArrayT), and also fixes linalg.matmul parameters to be positional-only.

I also snuck in an an additional overload that improves the return type if both input array-likes have the same dtype.

commit a8d7d13
Author: Joren Hammudoglu jhammudoglu@gmail.com
Date: Wed Oct 1 03:53:00 2025 +0200

TYP: Add missing ``rtol`` kwarg to ``linalg.pinv`` (#29845)

Apparently it was added in 2.0.0, but was missing from the stubs.

commit d9f83ec
Author: Joren Hammudoglu jhammudoglu@gmail.com
Date: Wed Oct 1 03:47:57 2025 +0200

TYP: Fix ``generic.__new__`` return type (#29842)