fix(parametric): wait for post-restart Node telemetry

[bm1549]

Motivation

Read the illustrated problem and fix report (Datadog AppGate)

The Node.js stable configuration tests restarted the test app and then read any telemetry already held by the test agent. A pre-restart configuration could be checked before the new runtime sent its app-started payload, making the assertion flaky.

Changes

Capture the current Node runtime ID before restart and wait for a different app-started runtime afterward. Read configuration only from that runtime, then use the existing direct assertions and newest sequence for each setting.

The regression tests cover a late post-restart runtime, a stale matching value from the old runtime, and a superseded configuration sequence.

Testing

• ./run.sh TEST_THE_TEST -q --disable-warnings --tb=no (381 passed, 1 xfailed)
• TEST_LIBRARY=nodejs ./run.sh PARAMETRIC --skip-parametric-build tests/parametric/test_config_consistency.py::Test_Stable_Config_Default::test_extended_configs (4 passed)
• ./format.sh

Workflow

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2. Work on you PR until the CI passes
3. Mark it as ready for review
   • Test logic is modified? -> Get a review from RFC owner.
   • Framework is modified, or non obvious usage of it -> get a review from the repository maintainers.

🚀 Once your PR is reviewed and the CI green, you can merge it!

Contact the repository maintainers if help is needed.

Reviewer checklist

• Anything but tests/ or manifests/ is modified ? I have approval from the repository maintainers.
• A docker base image is modified?
  • the relevant build-XXX-image label is present
• A scenario is added, removed or renamed?
  • Get a review from the repository maintainers.

[github-actions]

CODEOWNERS have been resolved as:

tests/test_the_test/test_test_agent.py                                  @DataDog/system-tests-core
tests/parametric/conftest.py                                            @DataDog/system-tests-core @DataDog/apm-sdk-capabilities
tests/parametric/test_config_consistency.py                             @DataDog/apm-sdk-capabilities
utils/docker_fixtures/_test_agent.py                                    @DataDog/system-tests-core