ci: update codeowners for gitlab suites

[emmettbutler]

This change updates codeowners for suites defined in gitlab. It also moves llmobs tests to their own file for this purpose.

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/tests/llmobs.yml                                                @DataDog/ml-observability
.github/CODEOWNERS                                                      @DataDog/python-guild @DataDog/apm-core-python
.gitlab/tests.yml                                                       @DataDog/python-guild @DataDog/apm-core-python
.gitlab/tests/contrib.yml                                               @DataDog/python-guild @DataDog/apm-core-python

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-09-06 19:59:42

Comparing candidate commit 18343b0 in PR branch emmett.butler/gitlab-owners with baseline commit 2730c1c in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 202 metrics, 2 unstable metrics.