[Human] -> [Athena] Clean up and split actions

[syifan]

There are too many actions now. I guess many of them are not useful. Please remove the ones that are not useful. Also, the accuracy validation may run too long. You can break it down into smaller ones.

[syifan]

[Athena]

PR #505 addresses this. Changes:

19 workflows → 9 workflows:

• Removed 10 redundant/broken workflows (h5-accuracy-report, polybench-sim, polybench-segmented, diana-statistical-validation, h4-multicore-accuracy, ci-health-monitor, ci-metrics-dashboard, performance-profiling, performance-regression-monitoring, cpi-comparison)
• Split the monolithic accuracy-report.yml (120 min single job) into 3 focused workflows:
  • accuracy-microbench.yml (~15 min)
  • accuracy-polybench.yml (~30 min, 3 parallel groups)
  • accuracy-embench.yml (~30 min)
• Consolidated 3 calibration workflows into 1 with suite selector
• Simplified triggers — changed rarely-used workflows to dispatch-only

Net: -2,406 lines of YAML, from 19 to 9 workflows.