Allow tracers to run all VMs

[sarahchen6]

Motivation

The recent 1.63.1 release of dd-trace-java failed on SSI system-tests that were only run for the release tag. Run all system-tests on dd-trace-java merge queue and master pipelines so that we catch release-blocking failures ASAP.

Changes

Introduce env var SYSTEM_TESTS_RUN_ALL_VMS that, when set by tracers to true, runs all VMs.

I tested this var in this dd-trace-java PR where we see all system tests run in this pipeline (vs current pipeline with only a subset of tests from a master run).

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:

utils/scripts/ci_orchestrators/external_gitlab_pipeline.py              @DataDog/system-tests-core
utils/scripts/ci_orchestrators/gitlab_exporter.py                       @DataDog/system-tests-core

[datadog-datadog-prod-us1]

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 2a7a635 | Docs | Datadog PR Page | Give us feedback!}