message: Less expensive random for upgrade test
  `/dev/urandom` on the github runners is sometimes slow. Random alphanumeric is all we need.
diff: @@ -253,7 +253,7 @@ function create_test_data() {
  for BASE in {1..2}
  do
  echo "Create the baseline file #${BASE}"
  - local RANDOM_DATA=$(tr -cd '[:alnum:]' < /dev/urandom | fold -w${TEST_DATA_BYTES} | head -n1)
  + local RANDOM_DATA=$(shuf -zer -n${TEST_DATA_BYTES} {A..Z} {a..z} {0..9})
  echo ${RANDOM_DATA} | tee -a data${BASE}.txt.tmp
  done
  