dvisvgm v2.13.4

[Karl Berry]

    Would it maybe be possible to exceptionally update dvisvgm to the
    current version of 2.13.4 during the year?

Akira has already updated the Windows binary.
Maybe that is enough?

Or, on
    https://github.com/mgieseki/dvisvgm/issues/183

MartinG suggested another workaround by setting an envvar.

  yes, it should be possible to [un]set `NEWPDF` via environment variable
  [`GS_OPTIONS`]
  (https://www.ghostscript.com/doc/9.56.1/Use.htm#Environment_variables),
  e.g. with `export GS_OPTIONS=-dNEWPDF=false`. Both the GS executable
  and the GS library consider this variable, so it should work in
  conjunction with dvisvgm as well.

I am not enthused about rebuilding now, but dvisvgm would be easier than
most, so ... not impossible. -k