Prevent 2-tuples from being normalized twice (#11007)

lib/elixir/test/elixir/code_normalizer/formatted_ast_test.exs

@@ -478,6 +478,16 @@ defmodule Code.Normalizer.FormatterASTTest do
       defp sample do
         [
           # comment
+          {:a, "~> 1.2"}
+        ]
+      end
+      """
+
+      assert_same ~S"""
+      defp sample do
+        [
+          # comment
+          {:a, "~> 1.2"},
           {:b, "~> 1.2"}
         ]
       end