fix: remove infinite loop risk from util functions

Author: sjbur

packages/devextreme/js/__internal/scheduler/utils/skipped_days.ts

@@ -30,6 +30,10 @@ export const getFirstVisibleDate = (
   skippedDays: number[],
   nextDate: (date: Date) => Date,
 ): Date => {
+  if (skippedDays.length >= 7) {
+    return new Date(start);
+  }
+
   let date = new Date(start);
   while (isDateSkipped(date, skippedDays)) {
     date = nextDate(date);

packages/devextreme/js/__internal/scheduler/workspaces/m_timeline.ts

@@ -108,8 +108,14 @@ class SchedulerTimeline extends SchedulerWorkSpace {
   }
 
   protected incrementDate(date) {
+    const skippedDays = this.option('skippedDays') ?? [];
+
+    if (skippedDays.length >= 7) {
+      return;
+    }
+
     date.setDate(date.getDate() + 1);
-    while ((this.option('skippedDays') ?? []).includes(date.getDay())) {
+    while (skippedDays.includes(date.getDay())) {
       date.setDate(date.getDate() + 1);
     }
   }