[typescript] Fix AnyComponent for functional components. (#12589)

A functional component does not return a ReactElement with the same props as its input, but a ReactElement with props of its child component.
The props of its child component can not be determined and are irrelevant for typing purposes.

packages/material-ui/src/index.d.ts

@@ -4,7 +4,7 @@ export { StyledComponentProps };
 
 export type AnyComponent<P = any> =
   | (new (props: P) => React.Component)
-  | ((props: P & { children?: React.ReactNode }) => React.ReactElement<P> | null);
+  | ((props: P & { children?: React.ReactNode }) => React.ReactElement<any> | null);
 
 export type PropsOf<C extends AnyComponent> = C extends new (props: infer P) => React.Component
   ? P