chore: Don't create OpenAI segments if ai_monitoring is disabled

[amychisholm03]

Description

OpenAI instrumentation should not create segments if ai_monitoring.enabled === false. This PR adds this missing logic and tests to assert it.

How to Test

npm run versioned:major openai

Related Issues

Closes #3622

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.71%. Comparing base (d1e90e4) to head (a8e0444).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3625      +/-   ##
==========================================
+ Coverage   89.39%   97.71%   +8.32%     
==========================================
  Files         437      438       +1     
  Lines       57537    57568      +31     
  Branches        1        1              
==========================================
+ Hits        51435    56254    +4819     
+ Misses       6102     1314    -4788     

Flag	Coverage Δ
integration-tests-cjs-20.x	73.48% <5.88%> (?)
integration-tests-cjs-22.x	73.52% <5.88%> (-0.03%)	⬇️
integration-tests-cjs-24.x	74.25% <5.88%> (?)
integration-tests-esm-20.x	52.66% <5.88%> (?)
integration-tests-esm-22.x	52.71% <5.88%> (?)
integration-tests-esm-24.x	53.80% <5.88%> (?)
unit-tests-20.x	89.06% <5.88%> (?)
unit-tests-22.x	89.09% <5.88%> (?)
unit-tests-24.x	89.10% <5.88%> (?)
versioned-tests-20.x	80.81% <100.00%> (-0.31%)	⬇️
versioned-tests-22.x	80.82% <100.00%> (-0.32%)	⬇️
versioned-tests-24.x	80.75% <100.00%> (-0.31%)	⬇️

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[jsumners-nr]

I suspect there's a better way of handling this than to replicate checks in multiple methods across multiple implementations. Perhaps something like:

class Subscriber {
	enable() {
		if (this.shouldEnable === false) {
			this.logger.trace(
				{ packageName: this.packageName },
				'Not subscribing to channel events. Instrumentation is disabled.'
			)
			return
		}

		// do the real stuff
	}
}

[amychisholm03]

Ideally, this would be enough. However, because collect_ai / ai_monitoring can be changed serverside, we have to check the config values after the subscribers have been setup/enabled.

Also, I wanted to maintain parity with the other AIM subscribers, and I'll likely refactor this ai_monitoring check logic in #3487