[chore] update workflow to add changelog before pushing

[codeboten]

This prevents the workflow from trying to push to an existing branch which it doesn't have permissions to do.

An example of the failure can be found here: https://github.com/open-telemetry/opentelemetry-collector/actions/runs/10291429328/job/28483659786

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.36%. Comparing base (b688e7a) to head (86f3120).

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10832      +/-   ##
==========================================
- Coverage   91.37%   91.36%   -0.02%     
==========================================
  Files         406      406              
  Lines       19007    19007              
==========================================
- Hits        17368    17366       -2     
- Misses       1282     1283       +1     
- Partials      357      358       +1     

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