otlp: Clients to close body uniformly

[mark-pictor-csec]

There were inconsistencies in closing the response body. For traces, the Close happened in a defer statement and any error was logged. Logs and metrics were less rigorous. It appeared Close() wasn't always called, and when it was, errors were returned sometimes and ignored at other times.

This applies the defer logic from traces to the other two and removes other Close() calls.

This was part of PR #5929, and has been split out as requested.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.6%. Comparing base (ac5caea) to head (bb09ba1).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #5954   +/-   ##
=====================================
  Coverage   84.6%   84.6%           
=====================================
  Files        272     272           
  Lines      22896   22897    +1     
=====================================
+ Hits       19389   19390    +1     
  Misses      3163    3163           
  Partials     344     344           

see 4 files with indirect coverage changes

[dmathieu]

Could you add a changelog entry? (the check wasn't failing, but it appears that's because your branch was a bit far behind main).

[mark-pictor-csec]

Could you add a changelog entry? (the check wasn't failing, but it appears that's because your branch was a bit far behind main).

I added it under Fixed - I assume that's where it belongs.

[pellared]

@mark-pictor-csec, thanks for your contribution ❤️

[mark-pictor-csec]

And thank you all for the massive amount of effort you put in!