fix(RAC): relax inputRef type on Checkbox, Switch, and Radio to accept callback refs

[timges]

Closes #10319

✅ 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:

CheckboxProps/CheckboxFieldProps, SwitchProps/SwitchFieldProps, and RadioProps/RadioFieldProps all typed inputRef as RefObject<HTMLInputElement | null>, which meant a ref callback could not be passed even though mergeRefs already accepts one and forwards it down to the underlying <input>.

This PR:

• Widens inputRef on all six prop interfaces from RefObject<HTMLInputElement | null> to Ref<HTMLInputElement | null>.
• Widens the internal useCheckboxAria helper's userProvidedInputRef parameter to match (its return type, the already-merged/normalized ref, stays RefObject since that's what the underlying useCheckbox/useCheckboxGroupItem hooks require).
• Fixes a latent bug found while testing this: Switch/SwitchField built the merged ref inline on every render instead of memoizing it like Checkbox/Radio do, so a callback ref would be torn down and re-invoked on every re-render rather than only on mount/unmount. Wrapped it in useMemo to match.

Added a "should support callback ref" test to Checkbox.test.js, Switch.test.js, and RadioGroup.test.js for both the deprecated and Field variants, asserting the callback is invoked with the input node on mount and its cleanup function is called exactly once on unmount.

Run:

yarn jest packages/react-aria-components/test/Checkbox.test.js packages/react-aria-components/test/Switch.test.js packages/react-aria-components/test/RadioGroup.test.js
yarn check-types

🧢 Your Project:

Spectrum Metrics

[reidbarber]

Thanks!