fix(endpoints): remove global map to avoid panic writes EE-3838 (#7404)

api/http/handler/endpoints/endpoint_list.go

@@ -19,8 +19,6 @@ const (
 	EdgeDeviceIntervalAdd        = 20
 )
 
-var endpointGroupNames map[portainer.EndpointGroupID]string
-
 // @id EndpointList
 // @summary List environments(endpoints)
 // @description List all environments(endpoints) based on the current user authorizations. Will
@@ -141,7 +139,7 @@ func sortEndpointsByField(endpoints []portainer.Endpoint, endpointGroups []porta
 		}
 
 	case "Group":
-		endpointGroupNames = make(map[portainer.EndpointGroupID]string, 0)
+		endpointGroupNames := make(map[portainer.EndpointGroupID]string, 0)
 		for _, group := range endpointGroups {
 			endpointGroupNames[group.ID] = group.Name
 		}

api/http/handler/endpoints/sort.go

@@ -39,8 +39,8 @@ func (e EndpointsByGroup) Less(i, j int) bool {
 		return false
 	}
 
-	groupA := endpointGroupNames[e.endpoints[i].GroupID]
-	groupB := endpointGroupNames[e.endpoints[j].GroupID]
+	groupA := e.endpointGroupNames[e.endpoints[i].GroupID]
+	groupB := e.endpointGroupNames[e.endpoints[j].GroupID]
 
 	return sortorder.NaturalLess(strings.ToLower(groupA), strings.ToLower(groupB))
 }