Switch to setting GALAXY_SLOTS using ROOT_MAX_THREADS for HTCondor submitted jobs

At the moment, Pulsar is using ROOT_MAX_THREADS (designed to control the ROOT data analysis framework from CERN) to set GALAXY_SLOTS. Switch to PYTHON_CPU_COUNT (controls the amount of CPUs that Python sees).

Author: kysrpex

pulsar/managers/util/job_script/CLUSTER_SLOTS_STATEMENT.sh

@@ -26,7 +26,7 @@ elif [ -n "$LSB_DJOB_NUMPROC" ]; then
 elif [ -n "$GALAXY_SLOTS" ]; then
     # kubernetes runner injects GALAXY_SLOTS into environment
     GALAXY_SLOTS=$GALAXY_SLOTS
-elif [ -n "$ROOT_MAX_THREADS" ]; then
+elif [ -n "$PYTHON_CPU_COUNT" ]; then
     # HTCondor sets a couple of environment variables read by various
     # frameworks to control the number of threads they are allowed to use. A
     # list can be found in the HTCondor docs (the list itself is configurable,
@@ -36,9 +36,8 @@ elif [ -n "$ROOT_MAX_THREADS" ]; then
     # configuration-macros.html#STARTER_NUM_THREADS_ENV_VARS
     #
     # Any of these variables can be used to set GALAXY_SLOTS. Set it using the
-    # variable ROOT_MAX_THREADS (designed to control the ROOT data analysis
-    # framework from CERN).
-    GALAXY_SLOTS="$ROOT_MAX_THREADS"
+    # variable PYTHON_CPU_COUNT (controls the amount of CPUs that Python sees).
+    GALAXY_SLOTS="$PYTHON_CPU_COUNT"
 else
     GALAXY_SLOTS="1"
     unset GALAXY_SLOTS_CONFIGURED