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-5953332
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1083991
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1317097
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-543669
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-543490
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-6056419
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-564897
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-459301
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-8367012
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-8707740
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1584063
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1584064
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-459302
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-469234
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1089809
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-459303
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-459304
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1020439
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-5725787
- https://snyk.io/vuln/SNYK-JAVA-IOVERTX-72443
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-2314893
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1070799
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1082234
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1082235
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-1082236
- https://snyk.io/vuln/SNYK-JAVA-IOVERTX-1018903
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-2812456
- https://snyk.io/vuln/SNYK-JAVA-IONETTY-6483812

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>3.9.4</vertx-version>
         <jackson-version>2.17.1</jackson-version>
         <jackson-databind>2.17.1</jackson-databind>
         <jackson-databind-nullable-version>0.2.6</jackson-databind-nullable-version>