This commit standardizes the way README files are handled during builds and publishes across all packages. The main changes include:

1. Removing the need for separate README-PYPI.md files by using a more flexible approach
2. Updating the prepare_readme.py script to handle relative links more robustly
3. Simplifying the build and publish workflows by removing redundant steps
4. Adding tests for the README preparation functionality

The changes make the build process more consistent across different packages and reduce duplication in the workflow files. The new approach also provides better handling of relative links in README files during package publication.

BREAKING CHANGE: The way README files are prepared for publication has changed, which may affect custom build processes that relied on the previous approach.

This commit adds mypy, pyright, and ruff linting checks for the scripts directory to ensure code quality and consistency across the project. The changes include:

- Adding mypy checks for the scripts directory
- Adding pyright checks for the scripts directory
- Adding ruff checks for the scripts directory

This helps maintain consistent code quality standards across all parts of the codebase.