Add changes to changes.xml

Author: FSchumacher

xdocs/changes.xml

@@ -64,6 +64,7 @@ Summary
   <h3>General</h3>
   <ul>
     <li><pr>6220</pr> Require Java 17 or later for running JMeter</li>
+    <li><pr>6274</pr> Change references to old MySQL driver to new class <code>com.mysql.cj.jdbc.Driver</code></li>
   </ul>
 
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