HPCC-12325 Making hpcc-run.sh run in parallel by default

Signed-off-by: Michael Jon Gardner <Michael.Gardner@lexisnexis.com>
Merge pull request #6544 from Michael-Gardner/HPCC-12325

HPCC-12325 Making hpcc-run.sh run in parallel by default

Reviewed-By: Xiaoming Wang <xiaoming.wang@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>