[tlbuild] tl25/dev: building failure on OpenBSD

[Robert Alessi]

Hi,

An attempt to build tl25/dev quickly failed on OpenBSD (upon entering
source/Work/doc/) with the following message:

```
Making all in doc
gmake[1]: Entering directory '/mnt/disk/robert/texlive-openbsd/source/Work/doc'
restore=: && backupdir=".am$$" && \
am__cwd=`pwd` && CDPATH="${ZSH_VERSION+.}:" && cd ../../doc && \
rm -rf $backupdir && mkdir $backupdir && \
if (/bin/sh '/mnt/disk/robert/texlive-openbsd/source/build-aux/missing' makeinfo --version) >/dev/null 2>&1; then \
  for f in ../../doc/tlbuild.info ../../doc/tlbuild.info-[0-9] ../../doc/tlbuild.info-[0-9][0-9] ../../doc/tlbuild.i[0-9] ../../doc/tlbuild.i[0-9][0-9]; do \
    if test -f $f; then mv $f $backupdir; restore=mv; else :; fi; \
  done; \
else :; fi && \
cd "$am__cwd"; \
if /bin/sh '/mnt/disk/robert/texlive-openbsd/source/build-aux/missing' makeinfo  --set INFO_SPECIAL_CHARS_WARNING=0 --disable-encoding -I ../../doc \
 -o ../../doc/tlbuild.info ../../doc/tlbuild.texi; \
then \
  rc=0; \
  CDPATH="${ZSH_VERSION+.}:" && cd ../../doc; \
else \
  rc=$?; \
  CDPATH="${ZSH_VERSION+.}:" && cd ../../doc && \
  $restore $backupdir/* `echo "./../../doc/tlbuild.info" | sed 's|[^/]*$||'`; \
fi; \
rm -rf $backupdir; exit $rc
makeinfo: unknown option -- set
Try `makeinfo --help' for more information.
gmake[1]: *** [Makefile:553: ../../doc/tlbuild.info] Error 1
gmake[1]: Leaving directory '/mnt/disk/robert/texlive-openbsd/source/Work/doc'
gmake: *** [Makefile:574: all-recursive] Error 1
+ echo 2
+ > exitstatus.txt 
done (exit status 2) Mon Apr 22 08:13:12 CEST 2024
```

Unfortunately I won't have a chance to look into this until June, for
which I am very sorry...

Thanks, -- Robert