`CheckboxGroup` has `aria-conditional-attr` violation

[joshblack]

Description

The CheckboxGroup and Checkbox components have an aria-conditional-attr violation from axe due to usage of aria-checked

The value of aria-checked should mirror the value of the input's checked property

Steps to reproduce

1. Visit the component storybook
2. Run axe
3. View issue titled: "ARIA attributes must be used as specified for the element's role"

Version

v36.x

Browser

No response