test: update flutter pub get location

Author: juliansteenbakker

.github/workflows/code-integration.yml

@@ -91,6 +91,7 @@ jobs:
           os_version: ">=18.1"
           model: "iPhone 15"
       - run: flutter pub get
+        working-directory: flutter_secure_storage/example
       - name: Pod Install
         working-directory: flutter_secure_storage/example
         run: |
@@ -100,4 +101,4 @@ jobs:
       - run: flutter build ios --simulator --target=integration_test/app_test.dart
         working-directory: flutter_secure_storage/example
       - run: flutter test integration_test
-        working-directory: flutter_secure_storage/example
+        working-directory: flutter_secure_storage/example