[extension/ballast] Remove the deprecated memory ballast extension

[TylerHelmuth]

Description

This PR removes the deprecated memory ballast extension and all the logic in place in memorylimiter and service that was using it.

Link to tracking issue

Related to #8343. I don't want to close it until the helm chart is updated.

Testing

Unit tests

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.23%. Comparing base (48b11ba) to head (420efda).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10671      +/-   ##
==========================================
+ Coverage   92.22%   92.23%   +0.01%     
==========================================
  Files         409      406       -3     
  Lines       19134    19101      -33     
==========================================
- Hits        17646    17618      -28     
+ Misses       1127     1123       -4     
+ Partials      361      360       -1     

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[mx-psi]

Can we possibly split this process in more steps?

For example, a first step before outright removal can be:

• Removing it from the Helm chart
• Removing support from it in the service (that is, fixing Change process_runtime_heap_alloc_bytes metric to include memory ballast size #8342) and documenting this
• Removing any mention of it on docs and examples on the opentelemetry org

Then a second step can be removing it from the official binaries while keeping a source-only release, and a final step would be removing the source code entirely.

I think this would solve our immediate issue and make the deprecation process more manageable (not all users would get this removed at the same time, so support requests are more easy to manage).

I know this is more annoying but

• this extension has been here since forever
• we don't know which users have been listening to our deprecations

so I think we need to be gentle and divide this into steps

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[mx-psi]

Have we seen any users complaining after open-telemetry/opentelemetry-collector-releases/pull/607? I see #10995, have we had any other reports?

If #10995 is the only one, I am comfortable merging this

[TylerHelmuth]

So far I've only seen #10995

[mx-psi]

Oki, then I would propose we wait until, say, Wednesday next week and merge if we don't get more reports