fix(package): binaries destination folder

[danielebriggi]

No description provided.

[Copilot]

Pull Request Overview

This PR fixes the binaries destination folder structure for the Python package by standardizing the package name from sqlite-vector to sqlite_vector and bumps the version to 0.9.26.

• Updates package name from sqlite-vector to sqlite_vector across documentation and configuration files
• Increments version number from 0.9.25 to 0.9.26 in the header file
• Adds conditional Test PyPI publishing support to the GitHub workflow

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/sqlite-vector.h	Version bump from 0.9.25 to 0.9.26
packages/python/download_artifacts.py	Updates binaries directory path to use underscore naming
packages/python/README.md	Updates documentation table to reflect new package naming
packages/python/MANIFEST.in	Updates include path to use underscore naming
.github/workflows/python-package.yml	Adds optional Test PyPI publishing functionality

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