gh-138122: Remove default duration for statistical profiling

[lkollar]

Instead of limiting profiling to 10s, let the process finish by default.

Towards #142927

• Issue: Implement PEP 799 – A dedicated profiling package for organizing Python profiling tools #138122

[pablogsal]

I think we still need to update the docs

[pablogsal]

I think sample.py still has references to duration_sec=10

[pablogsal]

Pushed a small fix with the items left and a (somehow related) bug I found while testing