Add otel code.stacktrace field

[SylvainJuge]

Motivation/summary

Adds the span.code.stacktrace field to store the code.stacktrace field added in otel semantic conventions: open-telemetry/semantic-conventions#435

Checklist

• decide on having a top-level field code.stacktrace or keep in within the span namespace with span.code.stacktrace. >> using code.stacktrace to avoid having to deprecate in the future.
• Update CHANGELOG.asciidoc
• Update package changelog.yml (only if changes to apmpackage have been made)
• Documentation has been updated

For functional changes, consider:

• Is it observable through the addition of either logging or metrics?
• Is its use being published in telemetry to enable product improvement?
• Have system tests been added to avoid regression?

How to test these changes

Related issues

Depends on elastic/apm-data#184 to be merged first, then updating this PR will be required to update the version of apm-data.

Depends on #12386 to be merged too.

[mergify]

This pull request does not have a backport label. Could you fix it @SylvainJuge? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-7.17 is the label to automatically backport to the 7.17 branch.
• backport-8./d is the label to automatically backport to the 8./d branch. /d is the digit.

NOTE: backport-skip has been added to this pull request.

[mergify]

This pull request is now in conflicts. Could you fix it @SylvainJuge? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b code-stacktrace upstream/code-stacktrace
git merge upstream/main
git push upstream code-stacktrace

[mergify]

This pull request is now in conflicts. Could you fix it @SylvainJuge? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b code-stacktrace upstream/code-stacktrace
git merge upstream/main
git push upstream code-stacktrace

[mergify]

This pull request is now in conflicts. Could you fix it @SylvainJuge? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b code-stacktrace upstream/code-stacktrace
git merge upstream/main
git push upstream code-stacktrace

[kruskall]

LGTM!

[marclop]

I verified this in ESS 8.13 latest BC. I modified sendotlp to set code.stacktrace as a span attribute.

@SylvainJuge is it expected that the code is only set in spans and not transactions?

[SylvainJuge]

Yes, only spans should have code.stacktrace.