Bump otel-appender-tracing version to 0.28

[lalitb]

This got missed out in #2635

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

All modified and coverable lines are covered by tests ✅

Project coverage is 79.0%. Comparing base (062c9d6) to head (f492e59).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #2637   +/-   ##
=====================================
  Coverage   79.0%   79.0%           
=====================================
  Files        120     120           
  Lines      22512   22512           
=====================================
  Hits       17791   17791           
  Misses      4721    4721           

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