fix(profiling): access lock acquired time only when the lock is held [backport 2.19]

[taegyunkim]

Manual backport of #11881 to 2.19

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-lock-acquired-at-e308547cffdca9f7.yaml     @DataDog/apm-python
ddtrace/profiling/collector/_lock.py                                    @DataDog/profiling-python

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-01-10 15:56:06

Comparing candidate commit 6262fbf in PR branch backport-11881-to-2.19 with baseline commit 8d79908 in branch 2.19.

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