Update vertx version to 4.5.21 (#110)

Author: cYKatherine

pom.xml

@@ -11,7 +11,7 @@
     <properties>
         <maven.compiler.source>21</maven.compiler.source>
         <maven.compiler.target>21</maven.compiler.target>
-        <vertx.version>4.5.18</vertx.version>
+        <vertx.version>4.5.21</vertx.version>
         <uid2-shared.version>9.1.0</uid2-shared.version>
     </properties>