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

Add regression coverage for stale values and values split across runtimes. The tests also check that the newest configuration sequence wins.

For Node.js, capture the current runtime ID before restart and wait for a different app-started runtime afterward. The test agent can now filter telemetry by runtime ID and keep polling until the complete expected configuration matches the newest sequence for each setting.

Testing

• ./run.sh TEST_THE_TEST -q --disable-warnings --tb=no (383 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

1. ⚠️ Create your PR as draft ⚠️
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 R&P team

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

🛟 #apm-shared-testing 🛟

Reviewer checklist

• Anything but tests/ or manifests/ is modified ? I have the approval from R&P team
• 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 R&P team

[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