fix(otel): Fix missing baggage

[sentrivana]

We snuck in a functional change in #3168 that led to a regression. Fixing this.

Fixes #3216

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.34%. Comparing base (0629094) to head (8fe9af8).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3218      +/-   ##
==========================================
+ Coverage   79.32%   79.34%   +0.01%     
==========================================
  Files         132      132              
  Lines       14218    14217       -1     
  Branches     2985     2984       -1     
==========================================
+ Hits        11279    11280       +1     
  Misses       2093     2093              
+ Partials      846      844       -2     

Files	Coverage Δ
...y_sdk/integrations/opentelemetry/span_processor.py	76.52% <100.00%> (+0.35%)	⬆️

... and 1 file with indirect coverage changes