Modified comprehensive_8dev_experiments.yaml from 20 num runs to 100

[danielwu7115]

What this PR does:

This PR updates the microbenchmark workload configuration for 8-device Host to Device and Device to Host (h2dd2h). Specifically, it:

• Increases the number of runs for the benchmark from 20 to 100.

Why these changes are needed:

• Increased Runs: The original 20 runs were insufficient to accurately characterize the performance distribution of this workload due to inherent run-to-run variability. Increasing num_runs to 100 provides a larger, more statistically robust dataset, ensuring more reliable and repeatable performance insights.

How these changes were implemented:

• The configuration value for num_runs was updated from 20 to 100 in Ironwood/configs/host_device/comprehensive_8dev_experiments.yaml.

How this was tested:

• Local verification to ensure the benchmark accepts the updated configuration and successfully executes for 100 runs.