Add error logging and clarifying comment based on code review feedback

Co-authored-by: ReneWerner87 <7063188+ReneWerner87@users.noreply.github.com>

testhelpers/tck/suite.go

@@ -320,8 +320,10 @@ func (s *StorageTestSuite[T, D, C]) TestGetExpired() {
 	s.Eventually(func() bool {
 		val, err := s.store.Get("temp_key")
 		if err != nil {
+			s.T().Logf("Unexpected error while checking if key expired: %v", err)
 			return false
 		}
+		// Storage implementations should return nil/empty slice for expired/non-existent keys
 		return len(val) == 0
 	}, 2*time.Second, 100*time.Millisecond, "Key should expire")
 }