Radio group should not autoselect on focus if a value is not currently selected

[fnimick]

Describe the feature in detail (code, mocks, or screenshots encouraged)

It makes sense to update value on focus if a value is selected - but if the radio group is unselected, merely tabbing or changing focus to the group should not immediately preselect the first option.

I believe it previously used to work this way prior to next for svelte 5.

What type of pull request would this be?

Enhancement

Provide relevant links or additional information.

No response