fix(profiling): clear sample pool after fork [backport 2.15]

[github-actions]

Backport 9de85e3 from #11350 to 2.15.

Tested with native tests

crossbeam::ArrayQueue uses Rust std::sync::atomic which doesn't seem to be consistent across fork() calls as std::mutex from C++ isn't. So we need to make sure, an equivalent of std::mutex::unlock() happens after fork.

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:

releasenotes/notes/profiling-sample-pool-461a108e068dea5b.yaml          @DataDog/apm-python
ddtrace/internal/datadog/profiling/dd_wrapper/src/sample_manager.cpp    @DataDog/profiling-python

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-11-11 22:17:33

Comparing candidate commit 9fbf850 in PR branch backport-11350-to-2.15 with baseline commit b40447e in branch 2.15.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 371 metrics, 53 unstable metrics.