[REMOVE] Cleanup deprecated thread pool settings

[reta]

Is your feature request related to a problem? Please describe.
Right now some of the thread pool settings are declared as deprecated and logged by deprecation logger:

[2022-03-25T16:00:21,595][DEPRECATION][o.o.d.c.s.Settings       ] [testSetLowerSettings] [thread_pool.test.max_queue_size] setting was deprecated in OpenSearch and will be removed in a future release! See the breaking changes documentation for the next major version.
[2022-03-25T16:00:21,596][DEPRECATION][o.o.d.c.s.Settings       ] [testSetLowerSettings] [thread_pool.test.min_queue_size] setting was deprecated in OpenSearch and will be removed in a future release! See the breaking changes documentation for the next major version.

Describe the solution you'd like
Cleanup deprecated thread pool settings in 3.0.0

Describe alternatives you've considered
Leave them there

Additional context
N/A

[reta]

@nknize @andrross do you guys know what is the plan for those? thanks!

[andrross]

It looks like the AutoQueueAdjustingExecutorBuilder itself was deprecated for removal due to being experimental and not being used. Seems like we can go ahead and take it out unless anyone has objections.

[andrross]

I don't think we need to get this change into the upcoming 2.0 release, but we can target it for 2.1.

[reta]

It will be breaking change, right? So next major like 3.0.0?

[andrross]

It will be breaking change, right? So next major like 3.0.0?

Of course, you're right, since there are configuration settings to remove. I still think we can pass on 2.0 since that is coming up rapidly and this doesn't seem critical. We can target 3.0 instead.