ci(tracer): avoids shutting down the global tracer in the main process

[mabdinur]

When the tracer is shutdown span aggregators are removed. If this is done outside of a subprocess it will impact the state of the tracer in future test runs. This PR ensures the tracer shutdown tests are only run in a subprocess.

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:

tests/tracer/test_propagation.py                                        @DataDog/apm-sdk-api-python
tests/tracer/test_tracer.py                                             @DataDog/apm-sdk-api-python

[datadog-dd-trace-py-rkomorn]

Datadog Report

Branch report: munir/debug-broken-tracer-test
Commit report: 4cd934e
Test service: dd-trace-py

✅ 0 Failed, 130 Passed, 1184 Skipped, 3m 39.65s Total duration (25m 11.27s time saved)

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-02-06 21:31:38

Comparing candidate commit c5f0eba in PR branch munir/debug-broken-tracer-test with baseline commit 1247ac2 in branch main.

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