feat: support template > script elements without type attribute

[smeijer]

The type attribute for script elements is optional, and defaults to text/javascript.

This PR add's support for untyped script elements in embed templates.

The following two examples, are now treated equal:

<template data-testing-playground>
  <script type="text/html">
    <button>one</button>
  </script>

  <script type="text/javascript">
    screen.getByRole('button');
  </script>
</template>

<template data-testing-playground>
  <script type="text/html">
    <button>one</button>
  </script>

  <script>
    screen.getByRole('button');
  </script>
</template>