[css-scrollbars] remove stray markup

Author: frivoal

css-scrollbars-1/Overview.bs

@@ -201,7 +201,7 @@ The scrollbar should nonetheless remain wide enough to be usable.
 (Implementers may wish to consult
 <a href="https://www.w3.org/TR/WCAG21/#target-size">WCAG 2.1 SC 2.5.5 Target Size</a>. [[WCAG21]])
 
-Note: Some platforms <del>may</del> only have a tiny scrollbar by default
+Note: Some platforms only have a tiny scrollbar by default
 which cannot be reasonably made thinner.
 In such cases, this value will behave as ''scrollbar-width/auto''.
 </dd>