Remove more dead code (#738)

Author: 72636c

src/private/SpacedHeading.css.ts

@@ -1,6 +1,4 @@
 import type { Stack } from 'braid-design-system';
 import type { ComponentProps } from 'react';
 
-export type HeadingLevel = 1 | 2 | 3 | 4 | 5 | 6;
-
 export type StackChildrenProps = Pick<ComponentProps<typeof Stack>, 'children'>;