avoid link level error with luatex

[u-fischer]

This needs (with lualatex)

\AddToHook{cmd/@make@specialcolbox/before}{%
  \setbox\@outputbox \vbox {%
    \boxmaxdepth \@maxdepth
    \pdflinkadjustlevel -1\relax
    \unvbox \@outputbox
  }%
}

see also latex3/tagpdf#120