fix: addSequence: clear rhs node Keys to ensure index is assigned

Author: antoinedeschenes

pkg/yqlib/operator_add.go

@@ -26,11 +26,16 @@ func toNodes(candidate *CandidateNode, lhs *CandidateNode) []*CandidateNode {
 
 	switch candidate.Kind {
 	case SequenceNode:
+		content := clone.Content
+		for _, node := range content {
+			node.Key = nil
+		}
 		return clone.Content
 	default:
 		if len(lhs.Content) > 0 {
 			clone.Style = lhs.Content[0].Style
 		}
+		clone.Key = nil
 		return []*CandidateNode{clone}
 	}