[Bug]: phone keyboard flickers when using number-field's action buttons

### Code of conduct

- [X] I agree to follow this project's code of conduct.

### Impacted component(s)

Number Field

### Expected behavior

When I tap the increment/decrement buttons on the number-field I expect the keyboard to stay closed/open.

### Actual behavior

When I tap the increment/decrement buttons on the number-field the keyboard flickers, opening and closing fast.

### Screenshots

https://github.com/user-attachments/assets/869e6729-90fa-42a9-9927-d192ca1b672f

### What browsers are you seeing the problem in?

Safari

### How can we reproduce this issue?

1. Go to number-field storybook ([here](https://opensource.adobe.com/spectrum-web-components/storybook/index.html?path=/story/number-field--decimals))
2. Click on increment/decrement multiple times
3. Observe the keyboard flickering

### Sample code or abstract reproduction which illustrates the problem

_No response_

### Severity

SEV 3

### Logs taken while reproducing problem

_No response_

Start with the Number Field decimals story in Storybook and reproduce the issue in Safari by repeatedly tapping the increment and decrement buttons. Trace the component's keyboard focus behavior during those actions, then verify that the keyboard remains consistently open or closed as expected without flickering.

Written by the indexing model from the issue text.