fix(llmobs): don't drop IO annotations equal to zero [backport 2.15]

[github-actions[bot]]

Backport 2f23eb28c6b4d98b6cac4f84edc2ee3c42095aad from #11044 to 2.15.

Fixes an issue where we are dropping I/O annotations that were equal to zero for workflow, task, agent and tool spans.

Checklist

• [x] 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

• [x] 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

[pr-commenter[bot]]

Benchmarks

Benchmark execution time: 2024-10-16 21:52:08

Comparing candidate commit b408fe556986f3e86aa6d8112d9312deb63bedd7 in PR branch backport-11044-to-2.15 with baseline commit c131afcce9bf9340c350ac3618d29b940fee2f86 in branch 2.15.

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

[erikayasuda]

Closing/Re-opening to trigger the build jobs

[github-actions[bot]]

CODEOWNERS have been resolved as:

releasenotes/notes/fix-numeric-annotations-7cf06b5ceb615282.yaml        @DataDog/apm-python
ddtrace/llmobs/_llmobs.py                                               @DataDog/ml-observability
tests/llmobs/test_llmobs_service.py                                     @DataDog/ml-observability