fix(Blankslate): Don't use Box to render heading when flag is enabled (#4857)

* Don't use Box to render heading when flag is enabled

* Create soft-tips-chew.md

Author: jonrohan

.changeset/soft-tips-chew.md

@@ -0,0 +1,5 @@
+---
+"@primer/react": patch
+---
+
+fix(Blankslate): Don't use Box to render heading when flag is enabled

packages/react/src/Blankslate/Blankslate.tsx

@@ -174,15 +174,15 @@ export type HeadingProps = React.PropsWithChildren<{
   as?: 'h1' | 'h2' | 'h3' | 'h4' | 'h5' | 'h6'
 }>
 
-function Heading({as = 'h2', children}: HeadingProps) {
+function Heading({as: Component = 'h2', children}: HeadingProps) {
   const enabled = useFeatureFlag('primer_react_css_modules')
+
+  if (enabled) {
+    return <Component className={cx('Blankslate-Heading', classes.Heading)}>{children}</Component>
+  }
+
   return (
-    <Box
-      as={as}
-      className={cx('Blankslate-Heading', {
-        [classes.Heading]: enabled,
-      })}
-    >
+    <Box as={Component} className={cx('Blankslate-Heading')}>
       {children}
     </Box>
   )