Add Prism::Node#newline! method type

Author: S-H-GAMELINKS

templates/sig/prism/node.rbs.erb

@@ -20,6 +20,7 @@ module Prism
     def to_dot: () -> String
     def tunnel: (Integer line, Integer column) -> Array[Prism::node]
     def deprecated: (*String) -> void
+    def newline!: (Array[untyped]) -> void
   end
 
   type node_singleton = singleton(Node) & _NodeSingleton