Opportunistic DoT support in unwind

Hi,

while 6.6 is just out, work for or 6.7 is already progressing. If you
want to help the project, please consider testing oppurtunistic DoT
support for unwind(8). See

https://marc.info/?l=openbsd-tech&m=157183457431388&w=2

unwind tries to provide secure DNS support, even in in adverse
conditions like the wifi some hotles provide. DoT is an important
piece of that puzzle.

Thanks!

-Otto