[chore] Allow sometimes skipping deprecation process when adding variadic arguments

[evan-bradley]

Description

Call out that unnamed types, e.g. the function signature of an exported function, should not be relied upon by API consumers. In particular, updating a function to be variadic will break users who were depending on that function's signature.

Link to tracking issue

Helps #9041

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.87%. Comparing base (aacb835) to head (64ff97b).

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10041      +/-   ##
==========================================
- Coverage   91.88%   91.87%   -0.02%     
==========================================
  Files         360      360              
  Lines       16725    16725              
==========================================
- Hits        15368    15366       -2     
- Misses       1020     1021       +1     
- Partials      337      338       +1     

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

[mx-psi]

I think this should still be considered a breaking change, it is not a common exception, and while it's not super frequent to pass functions as arguments in Go it can happen.

I would be in favor of adding an exception for making the two step deprecation process described on https://github.com/open-telemetry/opentelemetry-collector/blob/main/CONTRIBUTING.md#breaking-changes for changes like this, while acknowledging this is still breaking

[evan-bradley]

Got it, I misunderstood the intent of this section. I've added a section to our contributing document instead.

[codeboten]

Would be good to discuss this at the SIG this week to ensure everyone is in agreement on the exception

[codeboten]

Thanks @evan-bradley