fix: add missing validation to a test

Author: eduardo-garcia18

tests/resources/test_verifications.py

@@ -93,4 +93,5 @@ def test_retrieve_verification_invalid_govt(verification_with_govt_expired):
 def test_retrieve_verification_invalid_poa(verification_with_poa_expired):
     verification = verification_with_poa_expired
     assert not verification.proof_of_residency_validation.is_valid
-    assert verification.proof_of_residency_validation.error_codes
+    errors = verification.proof_of_residency_validation.error_codes
+    assert 'document.expired' in errors