Refactor firstNameMap creation in FalukantService for improved efficiency

- Simplified the construction of firstNameMap by removing unnecessary spread operator, enhancing performance and readability.

backend/services/falukantService.js

@@ -2987,7 +2987,7 @@ class FalukantService extends BaseService {
             ]);
             
             // Erstelle Maps für schnellen Zugriff
-            const firstNameMap = new Map([...firstNames, ...childFirstNames].map(fn => [fn.id, fn.name]));
+            const firstNameMap = new Map(firstNames.map(fn => [fn.id, fn.name]));
             const lastNameMap = new Map(lastNames.map(ln => [ln.id, ln.name]));
             const titleMap = new Map(titles.map(t => [t.id, t.labelTr]));
             const moodMap = new Map(moods.map(m => [m.id, m.tr]));