Enforce Gson version

Enforce Gson version. By doing so, we ensure we do not get an older Gson
 version from the axonserver-connector-java project, which was causing
 clashes with Spring.

#206

pom.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
-  ~ Copyright (c) 2010-2024. Axon Framework
+  ~ Copyright (c) 2010-2025. Axon Framework
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
   ~ you may not use this file except in compliance with the License.
@@ -148,6 +148,13 @@
                 </exclusion>
             </exclusions>
         </dependency>
+        <!-- Gson is only there to ensure we have a Spring-compatible version instead of pulling in an older version through the axon-server connector, transitively. -->
+        <!-- The Gson dependency can be removed once we're on an Axon Server Connector version with an upgraded gRPC version. -->
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>2.11.0</version>
+        </dependency>
         <!-- Database -->
         <dependency>
             <groupId>com.h2database</groupId>