fix: Remove lastSeenAt when exporting FeatureEnvironment (#4416)

Signed-off-by: andreas-unleash <andreas@getunleash.ai>

src/lib/features/export-import-toggles/export-import-service.ts

@@ -640,11 +640,13 @@ export default class ExportImportService {
                     ...rest,
                 };
             }),
-            featureEnvironments: featureEnvironments.map((item) => ({
-                ...item,
-                name: item.featureName,
-                lastSeenAt: item.lastSeenAt?.toISOString(),
-            })),
+            featureEnvironments: featureEnvironments.map((item) => {
+                const { lastSeenAt, ...rest } = item;
+                return {
+                    ...rest,
+                    name: item.featureName,
+                };
+            }),
             contextFields: filteredContextFields.map((item) => {
                 const { createdAt, ...rest } = item;
                 return rest;