feat: angular 18 update

Author: Angular2Guy

frontend/src/angular/angular.json

@@ -88,14 +88,14 @@
         "serve": {
           "builder": "@angular-devkit/build-angular:dev-server",
           "options": {
-            "browserTarget": "testproject:build"
+            "buildTarget": "testproject:build"
           },
           "configurations": {
             "production": {
-              "browserTarget": "testproject:build:production"
+              "buildTarget": "testproject:build:production"
             },
             "de": {
-              "browserTarget": "testproject:build:de"
+              "buildTarget": "testproject:build:de"
             }
           }
         },