Fix for #2677 (#2705)

* Update docs given https://github.com/yaml/go-yaml/pull/348

* Fix for https://github.com/mikefarah/yq/issues/2677

Depends on https://github.com/yaml/go-yaml/pull/348

* Test for https://github.com/mikefarah/yq/issues/2677

* Remove redundant check and add test case for explicit `!!merge` on `*+` traversal

* Bump go.yaml.in/yaml/v4 from 4.0.0-rc.4 to 4.0.0-rc.5

pkg/yqlib/candidate_node.go

@@ -46,7 +46,11 @@ const (
 func createStringScalarNode(stringValue string) *CandidateNode {
 	var node = &CandidateNode{Kind: ScalarNode}
 	node.Value = stringValue
-	node.Tag = "!!str"
+	if stringValue == "<<" {
+		node.Tag = "!!merge"
+	} else {
+		node.Tag = "!!str"
+	}
 	return node
 }