[DOCS] Drop 7.13 reference from earlier branches

Author: jrodewig

docs/reference/migration/migrate_7_9.asciidoc

@@ -173,10 +173,6 @@ The following node role settings are now deprecated:
 
 Use the {ref}/modules-node.html#node-roles[`node.roles` setting] instead.
 
-If you used the deprecated node role settings on a 7.13 or later cluster, you
-will have a {ref}/logging.html#deprecation-logging[deprecation log message] on
-each of your nodes indicating the exact replacement value for `node.roles`.
-
 *Impact* +
 To avoid deprecation warnings, discontinue use of the deprecated settings.
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