bug: Datetime selected day should not change when changing months or years in the wheel picker

### Prerequisites

- [X] I have read the [Contributing Guidelines](https://github.com/ionic-team/ionic-framework/blob/main/.github/CONTRIBUTING.md#creating-an-issue).
- [X] I agree to follow the [Code of Conduct](https://ionicframework.com/code-of-conduct).
- [X] I have searched for [existing issues](https://github.com/ionic-team/ionic-framework/issues) that already report this problem, without success.

### Ionic Framework Version

v7.x

### Current Behavior

Datetime currently has a confusing user experience where changing either the month or year through the wheel picker interface:



Results in the selected day applying in the working month:


In experiences with multiple selection (as shown) this is even more confusing, as it only applies the first selected day to the new working month/year.

### Expected Behavior

Ionic should not be doing this behavior at all. Changing the month or year should have no impact on the selections within the calendar grid.

For example, if you change the month through the arrow navigation:


This behavior does not occur. This is expected.

### Steps to Reproduce

1. Render a datetime and select a day
2. Change the month or year from the picker interface (clicking the button in the upper-left of the header)
3. Observe: The selected day is applied to the new month/year you are viewing.

### Code Reproduction URL

https://ionicframework.com/docs/api/datetime#multiple-date-selection

### Ionic Info

N/A

### Additional Information

_No response_

从 Datetime 组件及其 wheel picker 行为入手，使用链接的多日期选择复现。跟踪更改月份或年份时工作视图和所选值如何更新。完成标准是：更改月份或年份不会改变日历网格中现有的选择，包括多项选择，同时箭头导航继续按描述运行。

由索引模型根据 Issue 内容生成。