valid role, remove fallback role support note (#2297)

Author: WilcoFiers

_rules/role-attribute-valid-value-674b10.md

@@ -55,7 +55,7 @@ There are no assumptions.
 
 ### Accessibility Support
 
-Older browsers do not support more than one token in the value for a role attribute. If multiple values are used in the role attribute, the attribute is ignored in these browsers.
+There are no accessibility support issues known.
 
 ### Bibliography