fix: use the correct tracing id and attributes in logs when nested within a tracing span

[SF-Zhou]

Fixes #2824 and #1378.

Changes

#2438 has already extracted the trace ID and span ID information from the tracing span, but has not handled the attributes. For instance:

tracing::error_span!("outer-span", field1 = true, field2 = 233).in_scope(|| {
    tracing::error!("event");
});

in tracing::error!("event"), the body is processed, but field1 and field2 are ignored. This commit attempts to fix that issue.

Additionally, when using distributed tracing and calling set_parent to set the context, the currently obtained trace_id was incorrect. This PR also fixes this issue.

This fix has been validated in online production environments. For users with the same requirements, they can temporarily opt to use the patched opentelemetry-appender-tracing-patched crate.

Merge requirement checklist

• CONTRIBUTING guidelines followed
• Unit tests added/updated (if applicable)
• Appropriate CHANGELOG.md files updated for non-trivial, user-facing changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

Attention: Patch coverage is 89.04110% with 8 lines in your changes missing coverage. Please review.

Project coverage is 81.3%. Comparing base (10cf02c) to head (55799ee).

Files with missing lines	Patch %	Lines
opentelemetry-appender-tracing/src/layer.rs	83.3%	8 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #2924   +/-   ##
=====================================
  Coverage   81.3%   81.3%           
=====================================
  Files        126     126           
  Lines      24254   24312   +58     
=====================================
+ Hits       19736   19785   +49     
- Misses      4518    4527    +9     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[scottgerring]

Hey @SF-Zhou thanks for opening the PR!
Can you give a few more details on what exactly led to this?

[SF-Zhou]

Hey @SF-Zhou thanks for opening the PR! Can you give a few more details on what exactly led to this?

Sure. The description of the PR has been updated.

[scottgerring]

@bantonsson I think your eyes on this would be helpful!