👽️ Port the recent _core and lib numpy typing PRs

[jorenham]

This ports the following upstream changes:

• TYP: numpy._NoValue numpy#29170
• TYP: Accept dispatcher function with optional returns in _core.overrides numpy#29171
• TYP: any(None) and all(None) numpy#29176
• TYP: lib._iotools annotation improvements numpy#29177
• TYP: fix ravel_multi_index false rejections numpy#29184

Closes #581

[Copilot]

Pull Request Overview

This PR ports several upstream NumPy typing improvements from the main NumPy repository, focusing on type annotation refinements and interface updates across multiple modules.

• Improves type safety by adding more specific type annotations and updating generic type variables
• Updates function signatures to accept None values where appropriate in reduction functions
• Refines type definitions for better compatibility with typing checkers

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/numpy-stubs/lib/_iotools.pyi	Updates type annotations, renames validation kwargs class, and adds new utility functions
src/numpy-stubs/_core/overrides.pyi	Refactors type variables and introduces type aliases for better dispatcher typing
src/numpy-stubs/_core/fromnumeric.pyi	Adds None support to all() and any() function signatures
src/numpy-stubs/_core/_multiarray_umath.pyi	Changes parameter types from Sequence to SupportsLenAndGetItem
src/numpy-stubs/init.pyi	Exports additional _NoValue symbol from _globals

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