[chore] remove TODO from confmap code

[atoulme]

Remove a TODO comment on confmap/provider.go related to ChangeEvent. This struct is used extensively in providers that rely on changes such as:
https://github.com/signalfx/splunk-otel-collector/blob/main/internal/configsource/etcd2configsource/source.go#L84

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.49%. Comparing base (4bbb604) to head (aa196f9).

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #10278   +/-   ##
=======================================
  Coverage   92.49%   92.49%           
=======================================
  Files         387      387           
  Lines       18259    18259           
=======================================
  Hits        16888    16888           
  Misses       1025     1025           
  Partials      346      346           

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[TylerHelmuth]

For posterity, here is some history on that TODO:

• Refactor configmapprovider.Provider and Retrieved interfaces #4403
• Define a type for onChange func instead of func pointer #4656

[TylerHelmuth]

I agree that this pattern has been serving its purpose for years now. Even if there are improvements (which have not been identified in years of use), I think they are 2.0 concerns not 1.0 concerns

[atoulme]

I cannot discern if there is a concern or a follow up, but if there is, it might be best documented in an issue. In the mean time, I think this TODO should not be in the code.