Fix/numberfield format options input reset

[Wonchang0314]

Closes #1893
Related to #9899

Summary

When formatOptions is passed as an inline object literal (e.g. formatOptions={{ style: 'currency',
currency: 'USD' }}), every parent re-render creates a new object reference. This caused
useNumberFieldState to detect a "change" in formatOptions and overwrite the current inputValue with
the last committed number value — resetting whatever the user was typing mid-input.

This fix stabilizes the formatOptions reference inside useNumberFieldState using a useRef and a
shallow equality check. If the new formatOptions has the same key-value pairs as the previous one,
the old reference is reused, preventing a spurious inputValue reset. I though this approach is appropriate
because all values in Intl.NumberFormatOptions are primitives (strings, numbers, booleans), so
shallow equality is equivalent to deep equality.

✅ Pull Request Checklist:

• Included link to corresponding React Spectrum GitHub Issue.
• Added/updated unit tests and storybook for this change (for new code or code which already has tests).
• Filled out test instructions.
• Updated documentation (if it already exists for this component).
• Looked at the Accessibility Practices for this feature - Aria Practices

📝 Test Instructions:

1. Run the existing NumberField test suites to verify nothing is broken:
   yarn jest packages/react-aria-components/test/NumberField.test.js
   yarn jest packages/@adobe/react-spectrum/test/numberfield/NumberField.test.js
2. The two new regression tests specifically cover this fix:
   - "does not reset input value when parent re-renders with same formatOptions content" — a parent
   component with its own state re-renders while formatOptions is an inline object literal; the typed
   value must be preserved.
   - "does not reset input during typing when re-rendered with same formatOptions content" — same
   scenario via the rerender helper.
3. To manually verify: render a NumberField with formatOptions={{ style: 'currency', currency: 'USD'
   }} as an inline literal inside a component that re-renders on some other state change. Type a value
   without committing (no blur/Enter) and trigger the parent re-render — the typed value should no
   longer be reset.

🧢 Your Project: