calib-workflow.sh: CALIB_ASYNC_EXTRACTCOSMICS may be unset

The switch is defined (default 0) only by the O2DPG counterpart of the
cosmics wiring; with an O2DPG without it every async workflow stopped at
the test (unbound variable under set -u). Default to 0 here.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: matthias-kleiner

prodtests/full-system-test/calib-workflow.sh

@@ -79,7 +79,7 @@ if [[ $CALIB_ASYNC_EXTRACTTIMESERIES == 1 ]] ; then
   CONFIG_TPCTIMESERIES+=" --mult-max ${TPCTIMESERIES_MULT_MAX}"
   add_W o2-tpc-time-series-workflow "$DISABLE_ROOT_INPUT ${CONFIG_TPCTIMESERIES}"
 fi
-if [[ $CALIB_ASYNC_EXTRACTCOSMICS == 1 ]] ; then
+if [[ ${CALIB_ASYNC_EXTRACTCOSMICS:-0} == 1 ]] ; then
   # cosmic muons in collision data: TPC-only legs matched with the preset's selection, raw clusters of each cosmic -> o2_cosmics_full.root
   : ${COSMICS_PRESET:=physics-v1}
   COSMICS_ROAD_DETECTORS=