[Temporal] Remove test/staging/Temporal/v8/calendar-days-in-week.js

Already covered for PlainDate and PlainDateTime; add a new test for
ZonedDateTime.

Author: catamorphism

test/built-ins/Temporal/ZonedDateTime/prototype/daysInWeek/basic.js

@@ -0,0 +1,17 @@
+// Copyright (C) 2026 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-get-temporal.zoneddatetime.prototype.daysinweek
+description: Checking days in week for a "normal" case (non-undefined, non-boundary case, etc.)
+features: [Temporal]
+---*/
+
+const tests = [
+  new Temporal.ZonedDateTime(189357810123456789n, "UTC"),
+  new Temporal.ZonedDateTime(217178610123456789n, "UTC"),
+  new Temporal.ZonedDateTime(220893810123456789n, "UTC"),
+];
+for (const zonedDateTime of tests) {
+  assert.sameValue(zonedDateTime.daysInWeek, 7, `Seven days in the week of ${zonedDateTime}`);
+}