[UI components]: Update style helper docs for unstable

[oliverigor]

What problem are you trying to solve? 💡

complete https://github.com/Shopify/checkout-web/issues/23677 fix, that wasn't included in all versions

How are you solving it? 🛠️

• For NonPresentationalAccessibilityRole I took JF's suggestion and just duplicated a bit of code since generate-docs cannot handle Exclude property right, and to avoid future errors I opted to not use Pick property as well.
• For conditional styles I end up simplifying some of the types along with @ncardeli, and created a simplified version for docs only, that way we were able to avoid the infinite loop when trying to access the property on the docs.

Tophat 🎩

Spin Instance 🌀

https://shopify-dev.conditional-styles-doc-fixes.igor-deoliveiramartins.us.spin.dev/docs/api/checkout-ui-extensions

Before

After

-8ad4-d909d41d3da3">

Checklist

• I have 🎩'd these changes
• I have updated relevant documentation

[jamesvidler]

Looks good 👍. You'll just need to add a changeset for this as a 'patch'.

[ncardeli]