Update src/Chartjs/assets/src/controller.ts

Co-authored-by: Evert Harmeling <evertharmeling@gmail.com>

Author: smnandre

src/Chartjs/assets/src/controller.ts

@@ -12,7 +12,10 @@
 import { Controller } from '@hotwired/stimulus';
 import { Chart, registerables } from 'chart.js';
 
-Chart.register(...registerables);
+// ChartJs 3.x
+if (registerables != undefined) {
+    Chart.register(...registerables);
+}
 
 let isChartInitialized = false;