[debug] investigate otel plugin issue

[SylvainJuge]

What does this PR do?

Add extra debug info to investigate unexpected issue. Reported in the forum.

Checklist

• [ ] This is an enhancement of existing features, or a new feature in existing plugins
  • [ ] I have updated CHANGELOG.asciidoc
  • [ ] I have added tests that prove my fix is effective or that my feature works
  • [ ] Added an API method or config option? Document in which version this will be introduced
  • [ ] I have made corresponding changes to the documentation
• [ ] This is a bugfix
  • [ ] I have updated CHANGELOG.asciidoc
  • [ ] I have added tests that would fail without this fix
• [ ] This is a new plugin
  • [ ] I have updated CHANGELOG.asciidoc
  • [ ] My code follows the style guidelines of this project
  • [ ] I have made corresponding changes to the documentation
  • [ ] I have added tests that prove my fix is effective or that my feature works
  • [ ] New and existing unit tests pass locally with my changes
  • [ ] I have updated supported-technologies.asciidoc
  • [ ] Added an API method or config option? Document in which version this will be introduced
  • [ ] Added an instrumentation plugin? Describe how you made sure that old, non-supported versions are not instrumented by accident.
• [ ] This is something else
  • [ ] I have updated CHANGELOG.asciidoc

[apmmachine]

:green_heart: Build Succeeded

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Build stats

• Start Time: 2022-09-13T08:02:26.140+0000

• Duration: 57 min 23 sec

Test stats :test_tube:

Test	Results
Failed	0
Passed	3151
Skipped	36
Total	3187

:green_heart: Flaky test report

Tests succeeded.

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