Missing data file for parallel-download workflow

[McLavish]

Commit 7c7f67b is missing the data-size.txt file

I could not find the original dataset used in their paper, so I had to regenerate a random dataset

mkdir -p benchmarks-data/600.workflows/631.parallel-download
python3 - <<'PY'
import os, random
size = 2 ** 20      # 1 MiB for the “test” size; adjust as needed
path = f"benchmarks-data/600.workflows/631.parallel-download/data-{size}-bytes.txt"
total = 0
with open(path, "w") as f:
    while total < size:
        chunk = str(random.randint(0, 255)) + "\n"
        f.write(chunk)
        total += len(chunk)
print(f"Wrote {path} ({total} bytes)")
PY

under:

benchmarks-data/600.workflows/631.parallel-download