This update removes an outdated technique (useLayoutEffect) that was causing performance issues in the Gantt chart. The change utilizes modern React signals and useEffect hooks to ensure the chart updates efficiently, aligning with the latest Odoo technology.

Replaces useLayoutEffect with a signal(null) callback ref via t-ref and useEffect, which auto-tracks the signal read inside the callback.

WHY: useLayoutEffect is removed in OWL3