Applies .selected styles to [aria-selected=true]

[flavianunes]

• Fixes: .selected selectors should always include [aria-selected=true] #790

I picked the first option from @shawnbot suggestions for its simplicity.

/cc @primer/ds-core

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[shawnbot]

This is great, thank you @flavianunes! ❤️

Our team is a bit busy with Universe and planning this week, but I will take a look at this as soon as I can. We don't have a minor release scheduled at this time, but I would love for this to be included in #925 (v14.0) unless we have a good reason to release before then.

[flavianunes]

Oops, I committed some other issue in the same branch, sorry! I will divide this in two PRs later

[flavianunes]

Oops, I committed some other issue in the same branch, sorry! I will divide this in two PRs later

I have fixed it

[simurai]

@flavianunes Thanks for contributing. 🙇

👍 I'll merge this already into #1006 so we can test CI and also update the docs.