Fix star comment non-idempoteny

[infinisil]

Previously, empty trailing lines in star comments would only get stripped after the second formatting, e.g.:

Original:

{
  /* foo
   * bar
   *
   */
}

After one formatting:

{
  /*
    foo
    bar

  */
}

After two formattings (and newly already after the first)

{
  /*
    foo
    bar
  */
}

---

This work is sponsored by Antithesis ✨

[github-actions]

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