[9.0] Update OTel components to v0.120.x

[swiatekm]

What does this PR do?

Updates OTel components to v0.120.0 in the 9.0 branch. The update for other branches in #6912 is currently blocked. We've unblocked it in 9.0 through #7023, because it blocks other changes that need to land for 9.0 release.

Why is it important?

It unblocks #6937, which should be in 9.0.

Checklist

• I have read and understood the pull request guidelines of this project.
• I have made corresponding changes to the documentation
• I have added an entry in ./changelog/fragments using the changelog tool

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[elasticmachine]

💔 Build Failed

• Buildkite Build
• Commit: e8e1fef

Failed CI Steps

• Unit tests - Windows 2016
• null

History

cc @swiatekm

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube

[swiatekm]

Got a K8s test failure:

=== Failed
=== FAIL: testing/integration TestOtelKubeStackHelm/helm_kube-stack_operator_standalone_agent_kubernetes_privileged (334.06s)
    otel_helm_test.go:122:
        	Error Trace:	/opt/buildkite-agent/builds/bk-agent-prod-gcp-1740576462608313681/elastic/elastic-agent-extended-testing/testing/integration/otel_helm_test.go:122
        	            				/opt/buildkite-agent/builds/bk-agent-prod-gcp-1740576462608313681/elastic/elastic-agent-extended-testing/testing/integration/otel_helm_test.go:96
        	Error:      	Condition never satisfied
        	Test:       	TestOtelKubeStackHelm/helm_kube-stack_operator_standalone_agent_kubernetes_privileged
        	Messages:   	at least 4 agent containers should be checked
=== FAIL: testing/integration TestOtelKubeStackHelm (342.70s)

in https://buildkite.com/elastic/elastic-agent-extended-testing/builds/7694#01954270-d4c5-4926-8442-4861f27bedea.

[swiatekm]

Also got what looks like an ESS problem:

Error: error running test: failed to check for cloud 9.0.0-SNAPSHOT [stack_id: 900-SNAPSHOT, deployment_id: 4711e5467e8d4f109f2ef465fb8535ab] to be ready: context deadline exceeded