Update testcontainers version to 1.21.4

Author: vietj

vertx-web-sstore-infinispan/pom.xml

@@ -144,7 +144,7 @@
     <dependency>
       <groupId>org.testcontainers</groupId>
       <artifactId>testcontainers</artifactId>
-      <version>1.15.2</version>
+      <version>1.21.4</version>
       <scope>test</scope>
     </dependency>
     <dependency>