remove the duplicates in department Name

src/controllers/departmentController.js

@@ -1128,14 +1128,14 @@ const getDepartmentsByName = async (officeName, city, departmentName) => {
         .select("departmentName -_id")
         .lean();
   
-      return result.map(doc => doc.departmentName);
+      // Remove duplicate department names
+      return [...new Set(result.map(doc => doc.departmentName))];
     } catch (error) {
       console.error("Error fetching departments by city:", error);
       throw new Error("Error fetching departments by city.");
     }
   };
   
-
   // API route handler
   exports.getDepartmentsByCity = async (req, reply) => {
     try {
@@ -1156,3 +1156,4 @@ exports.getDepartmentsByCity = async (req, reply) => {
       reply.status(500).send({ message: error.message });
     }
   };
+