✨ Add new composed sensor for Indexed tariff

• ✨ Add new price sensors: Market adjustment (from ESIOS API indicator 2108), and Indexed tariff (as composed price sensor calculated as PVPC - ADJUSTMENT), from first-time contributor @MiguelAngelLV in #69 🍻, and some adjustments in #70
• 🎨 pre-commit updates and change to ruff + ruff-format instead of black and isort
• 🚀 Bump minor version and update deps and CHANGELOG.md