[PROF-6559] Mark Ruby CPU Profiling 2.0 as being in beta

[ivoanjo]

What does this PR do?:

This PR collects a few small changes needed before releasing the new Ruby profiler bits ("CPU Profiling 2.0") as opt-in (that is, disabled by default) public beta.

I recommend reviewing commit-by-commit.

Motivation:

We're finally ready to start telling customers they can enable this new mode.

Additional Notes:

(N/A)

How to test the change?:

Change includes test coverage (the little code that is affected).

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.32%. Comparing base (ec7b868) to head (91cc4c5).
⚠️ Report is 7784 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2489   +/-   ##
=======================================
  Coverage   98.32%   98.32%           
=======================================
  Files        1118     1120    +2     
  Lines       60351    60401   +50     
=======================================
+ Hits        59339    59390   +51     
+ Misses       1012     1011    -1     

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