fix: samples/client/petstore/java/vertx-no-nullable/pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-14423947

Author: snyk-bot

samples/client/petstore/java/vertx-no-nullable/pom.xml

@@ -264,7 +264,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <vertx-version>3.5.2</vertx-version>
+        <vertx-version>4.5.23</vertx-version>
         <jackson-version>2.19.2</jackson-version>
         <jackson-databind>2.19.2</jackson-databind>
         <jackson-databind-nullable-version>0.2.7</jackson-databind-nullable-version>