♿️(frontend) hide avatar initials from sr to avoid duplicate names

prevents screen readers from announcing participant names twice

Signed-off-by: Cyril <c.gromoff@gmail.com>

src/frontend/src/components/Avatar.tsx

@@ -68,6 +68,7 @@ export const Avatar = ({
       {...props}
     >
       <span
+        aria-hidden="true"
         className={css({
           marginTop: '-0.3rem',
         })}