Squash of two overlapping fixes that both addressed ASV benchmark-regression
CI failures due to missing S3 baseline data:> 1. Make the job skip when no S3 baseline exists (e0239ef)
> 2. Add baseline check logic with .benchmark-baseline file (2d628bd)> Combined approach detects S3 availability, creates baseline marker file,
and gracefully skips regression when no baselines are available rather than
failing. Also updates ASV config and noxfile to support this resilience
ISSUES CLOSED: #10378
HAL9000
freemo
