Read Me First: Remove reference to Internet Explorer in browser suppo…

…rt section (pull #2683)

Per consensus of the 2023-04-25 meeting of the ARIA Authoring
Practices Task Force (https://www.w3.org/2023/04/25-aria-apg-minutes.html), remove mention of Internet Explorer from the browser support section.

content/practices/read-me-first/read-me-first-practice.html

@@ -72,7 +72,6 @@ <h2>Browser and Assistive Technology Support</h2>
         </p>
         <p>
           Similarly, JavaScript and CSS in this guide is written to be compatible with the most recent version of Chrome, Firefox, and Safari at the time of writing.
-  Some JavaScript and CSS may not function correctly in Internet Explorer.
         </p>
         <p>
           Except in cases where the ARIA Working Group and other contributors have overlooked an error,