Fix Combobox hidden input default value causing React warnings (name prop)

[sookmax]

Closes #6327

It just occurred to me that it might also be nice to update the type for selectedKey from Key to Key | null.
Should I include that as well? Or maybe it's better to address it when converting packages/@react-stately/list to TS strict later (I don't see it on the typescript-strict-plugin list in tsconfig.json).

react-spectrum/packages/@react-stately/list/src/useSingleSelectListState.ts

Lines 25 to 34 in cf0846e

	export interface SingleSelectListState<T> extends ListState<T> {
	/** The key for the currently selected item. */
	readonly selectedKey: Key,
	/** Sets the selected key. */
	setSelectedKey(key: Key | null): void,
	/** The value of the currently selected item. */
	readonly selectedItem: Node<T>
	}

✅ 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:

Story

• Visit http://localhost:9003/?path=/story/react-aria-components--combo-box-example&providerSwitcher-express=false&strict=true
• Open up the inspector and check there's no React warnings about 'uncontrolled components'

🧢 Your Project:

[snowystinger]

Probably easier to address the ts strict separately, I suspect it'll be non-trivial. But if it's easy, then feel free to add it.

Would you mind adding a name to a combobox test? It'll log the warning and we fail the tests if any logs are in our output.

[sookmax]

Probably easier to address the ts strict separately, I suspect it'll be non-trivial. But if it's easy, then feel free to add it.

I agree. I'll take a look later if I have some down times 😄

Would you mind adding a name to a combobox test? It'll log the warning and we fail the tests if any logs are in our output.

This is cool! I verified the React warnings result in test failures when the name prop was added and the fix was removed. And yes I added name to TestComboBox in ComboBox.test.js.