Fixes
refactor: rely on sqlx migration tracking
Removes the custom migration tracking implementation, uses sqlx's migrator directly for framework migrations, and fixes release PR creation to target the correct GitHub repository.
breaking: upgrade sqlx and move single runner construction to a builder
Upgrades sqlx to 0.9.0-alpha.1, adds configurable migration tracking tables through the storage and single-runner builders, and removes the old SingleRunner::new and SingleRunner::with_config constructors.