🐛 fix failing abstract number binop type-tests

[jorenham]

This backwards incompatible with NumPy, because this removes the type-unsafe number.__[r]floordiv__ dunder methods.

This additionally fixes the scalar-binop testgen script, so that stops skipping the generation of all timedelta and datetime rejectection tests.
It now also generates way less trivial rejection tests for the bitwise and modular operators.

[Copilot]

Pull Request Overview

This PR addresses failing abstract binop type-tests by removing the type-unsafe dunder methods from numpy.number and by enhancing the test generation for scalar binary operations.

• Updates operator mappings from symbols to descriptive names for datetime, timedelta, and bitwise operations.
• Adjusts filtering logic in scalar test generation for both built-in and abstract types.
• Updates documentation to reflect the removal of number floordiv methods and fixes a spelling error.

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

File	Description
tool/testgen.py	Improves operator mappings, name filtering, and rejection logic in scalar binary operation test generation.
docs/user_guide/differences.md	Updates documentation to correctly describe the removal of certain operations and fixes a spelling error.

Comments suppressed due to low confidence (2)

tool/testgen.py:671

• [nitpick] Consider replacing the magic string set for rejection with a named constant to improve code clarity and maintainability.

            reject |= {"bhilBHILefdgFDG", "FDG", "F", "D", "G"}

tool/testgen.py:675

• [nitpick] Using set("FGM") may be unclear; consider using a descriptive constant or a more explicit data structure to document the intent behind these ignored types.

            ignore |= set("FGM")