[Benchmarks] Migrate linux throughput tests (#6765)

## Summary of changes
This PR enables running the Linux based throughput tests through the
Benchmarking platform on Gitlab.
The tests are setup to run:
- On commit to the `master` branch
- On schedule if `BENCHMARK_RUN` is set to `"true"` for the scheduled
pipeline.
- On manual trigger (keep in mind that it requires build artifacts from
the Azure Pipeline)

The results can be checked on [the following
dashboard](https://ddstaging.datadoghq.com/dashboard/rgu-p7u-5fq?fromUser=false&refresh_mode=sliding&from_ts=1741708646144&to_ts=1741881446144&live=true)
## Reason for change
- The throughput tests previously running on AzDo have been
decommissioned.
- BP introduces more [repeatable
results](https://ddstaging.datadoghq.com/dashboard/rgu-p7u-5fq?fromUser=true&refresh_mode=paused&from_ts=1741688752256&to_ts=1741690131344&live=false)
## Implementation details
- We got rid of the dependency to Crank
- Changed the load tester from Bombardier (Crank) to K6 
- Using dedicated CPU cores for the load tester yields repeatable
results as opposed to running the load tester and system under test on
the same set of cores.

Author: faydef

.gitlab-ci.yml

@@ -201,4 +201,17 @@ benchmark-serverless-trigger:
     UPSTREAM_PROJECT_NAME: $CI_PROJECT_NAME
     UPSTREAM_GITLAB_USER_LOGIN: $GITLAB_USER_LOGIN
     UPSTREAM_GITLAB_USER_EMAIL: $GITLAB_USER_EMAIL
+
+macrobenchmarks:
+  stage: benchmarks
+  needs: [ ]
+  trigger:
+    include: .gitlab/benchmarks/macrobenchmarks.yml
+  allow_failure: true
+  rules:
+    - if: '$CI_PIPELINE_SOURCE == "push" && $CI_COMMIT_BRANCH == "master"'
+      when: always
+    - if: '$CI_PIPELINE_SOURCE == "schedule" && $BENCHMARK_RUN == "true"'
+      when: always
+    - when: manual