feat(datetime): ionChange will only emit from user committed changes (#26083)

resolves #20873 resolves #24452

BREAKING CHANGE

- `ionChange` is no longer emitted when the `value` property of `ion-datetime` is modified externally. `ionChange` is only emitted from user committed changes, such as clicking or tapping a date.

- Datetime no longer automatically adjusts the `value` property when passed an array and `multiple="false"`. Developers should update their apps to ensure they are using the API correctly.

core/src/components/datetime-button/datetime-button.tsx

@@ -126,7 +126,7 @@ export class DatetimeButton implements ComponentInterface {
        * text in the buttons.
        */
       this.setDateTimeText();
-      addEventListener(datetimeEl, 'ionChange', this.setDateTimeText);
+      addEventListener(datetimeEl, 'ionValueChange', this.setDateTimeText);
 
       /**
        * Configure the initial selected button

core/src/components/datetime-button/test/multiple/datetime-button.e2e.ts

@@ -73,12 +73,12 @@ test.describe('datetime-button: multiple selection', () => {
     await page.waitForSelector('.datetime-ready');
 
     const datetime = page.locator('ion-datetime');
-    const ionChange = await page.spyOnEvent('ionChange');
+    const ionValueChange = await page.spyOnEvent('ionValueChange');
     const dateButton = page.locator('#date-button');
     await expect(dateButton).toHaveText('2 days');
 
     await datetime.evaluate((el: HTMLIonDatetimeElement) => (el.value = ['2022-06-01', '2022-06-02', '2022-06-03']));
-    await ionChange.next();
+    await ionValueChange.next();
 
     await expect(dateButton).toHaveText('3 days');
   });