Remove Example Experiment registration

[dkotter]

What?

Closes #119

Remove the registration of our Example Experiment.

Why?

We have an Example Experiment in place which is useful for those looking to contribute or get some ideas on how things can be set up. But this Experiment doesn't actually add any useful functionality and it can be confusing to have this shown in our settings screen. For now we're leaving the code in place but we don't want this to be an Experiment someone can turn on.

How?

• Removes the Example Experiment from our list of default Experiments we register
• Updates our unit tests to account for this

Testing Instructions

Go to the AI Experiments settings page and ensure you no longer see a settings section for the Example Experiment

[github-actions]

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Co-authored-by: dkotter <dkotter@git.wordpress.org>
Co-authored-by: jeffpaul <jeffpaul@git.wordpress.org>

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 28.71%. Comparing base (4bbc5ea) to head (b7c8bdb).
⚠️ Report is 14 commits behind head on develop.

Additional details and impacted files

@@              Coverage Diff              @@
##             develop     #121      +/-   ##
=============================================
- Coverage      29.37%   28.71%   -0.67%     
- Complexity       145      153       +8     
=============================================
  Files             14       14              
  Lines            885      902      +17     
=============================================
- Hits             260      259       -1     
- Misses           625      643      +18     

Flag	Coverage Δ
unit	28.71% <ø> (-0.67%)	⬇️

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[JasonTheAdams]

Makes sense! 👍