"as" polymorphic prop doesn't apply correct prop types in v6

[nikmilson]

It's great, that styled-components now provide its own types. However I believe, there's a regression in comparison to @types/styled-components. My apologies in advance if I misunderstood the concept. Otherwise if the bug will be confirmed, I might consider creating a PR with a fix.

Environment

No need, since it's generic issue applicable to all typescript environments. Code sandboxes are provided below.

Reproduction

• styled-components@6 (broken ts): https://codesandbox.io/s/admiring-thunder-dwhrrk?file=/src/App.tsx
• styled-components@5 (working): https://codesandbox.io/s/brave-murdock-jg49jc?file=/src/App.tsx

Please give the code sandboxes a bit of time to init the environment, so the errors shown at the beginning will disappear.

Steps to reproduce

1. Create a React component with a required prop
2. Wrap it in styled
3. Render the styled component, but pass another component/HTML element without the required prop via "as" polymorphic prop

Expected Behavior

When using "as" polymorphic prop a styled component should expect properties of the passed component, not originally wrapped component.

Actual Behavior

Typescript error, example from the code sandbox above:

Property 'requiredProp' is missing in type '{ children: string; as: "button"; }' but required in type 'FastOmit<Substitute<FastOmit<{ className?: string | undefined; requiredProp: string; }, never>, Substitute<{}, Omit<DetailedHTMLProps<ButtonHTMLAttributes<HTMLButtonElement>, HTMLButtonElement>, "ref"> & { ...; }>>, keyof ExecutionProps>'.