[backend] fix(agents): fixed an hibernate detached issue when trying to fetch tags from an endpoint

Author: impolitepanda

openaev-api/src/main/java/io/openaev/service/EndpointService.java

@@ -320,6 +320,7 @@ public Endpoint updateEndpoint(
    * @param existingAgents in the database
    * @return OpenAEV agents
    */
+  @Transactional
   public List<Agent> syncAgentsEndpoints(
       List<AgentRegisterInput> inputs, List<Agent> existingAgents) {
     List<Agent> agentsToSave = new ArrayList<>();
@@ -418,6 +419,9 @@ public List<Agent> syncAgentsEndpoints(
     if (executor != null) {
       for (Asset asset : endpointsToSave) {
         if (asset instanceof Endpoint ep) {
+          if (ep.getId() != null) {
+            ep = this.getEndpoint(ep.getId());
+          }
           addSourceTagToEndpoint(ep, executor);
         }
       }