Fix interaction of top-level divisions `part` or `chapter` with
unnumbered headers when emitting LaTeX. Headers are ensured to be
written using stared commands (like `\subsection*{}`).
Fixes: #3272
Fix interaction of top-level divisions `part` or `chapter` with
unnumbered headers when emitting LaTeX. Headers are ensured to be
written using stared commands (like `\subsection*{}`).
Fixes: #3272