chore, request ANSI-C code off gperf explicitly

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'bld/dist' into next

* bld/dist:
  chore, request ANSI-C code off gperf explicitly
fix to fix, bring back errno errors for duration strings

dt_io_strpdtdur() and dt_io_strpdtrnd() set errno to ERANGE sometimes.

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'code/hygiene' into next

* code/hygiene:
  fix to fix, bring back errno errors for duration strings