Make the test suite pass on TruffleRuby and add it in CI

[eregon]

No description provided.

[eregon]

I tried to add a test to validate this change but couldn't find a way to trigger this case.
I tried things like:

    def test_search_string_simple
      results = search(%{"#{'abc'}"}, "StringLiteral[parts: [TStringContent[value: 'abc']]]")

      assert_equal 1, results.length
    end

    def test_search_symbol_simple
      puts %s{:"#{'abc'}"}
      puts ':"#{\'abc\'}"'
      results = search(':"#{\'abc\'}"', ':abc')
      results = search(':"#{\'abc\'}"', ':"#{\'abc\'}"')
      results = search(%{"#{'abc'}"}, "DynaSymbol[parts: [TStringContent[value: 'abc']]]")

      assert_equal 1, results.length
    end

But none seem to match this specific condition.