- Remove debug printing in callstats.py
- Handle non-version nested JSON files better in callstats.html
- Harden RCS extraction from telemetry JSON files

Change-Id: Ied921e54e6281a456c0a6369d797c21785080036
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3471856Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79155}