ci: move pr/regression check to benchmarks-report stage

[brettlangdon]

We do not always run the serverless benchmarks job, this means that the CI config is invalid in those cases since regression check has an explicit dependency on serverless benchmarks.

Checklist

• PR author has checked that all the criteria below are met
• The PR description includes an overview of the change
• The PR description articulates the motivation for the change
• The change includes tests OR the PR description describes a testing strategy
• The PR description notes risks associated with the change, if any
• Newly-added code is easy to change
• The change follows the library release note guidelines
• The change includes or references documentation updates if necessary
• Backport labels are set (if applicable)

Reviewer Checklist

• Reviewer has checked that all the criteria below are met
• Title is accurate
• All changes are related to the pull request's stated goal
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Newly-added code is easy to change
• Release note makes sense to a user of the library
• If necessary, author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance policy

[github-actions]

CODEOWNERS have been resolved as:

.gitlab-ci.yml                                                          @DataDog/apm-core-python
.gitlab/benchmarks.yml                                                  @DataDog/python-guild @DataDog/apm-core-python

[datadog-dd-trace-py-rkomorn]

Datadog Report

Branch report: brettlangdon/benchmarks-report.stag
Commit report: b64ac56
Test service: dd-trace-py

✅ 0 Failed, 130 Passed, 1468 Skipped, 4m 35.46s Total duration (36m 23.5s time saved)

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-01-24 20:12:42

Comparing candidate commit b64ac56 in PR branch brettlangdon/benchmarks-report.stag with baseline commit b90fa38 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 394 metrics, 2 unstable metrics.