Add comments to package dependency to clarify the direction

[reyang]

I think this will help to clarify the direction and also help to provide context/clarity to contributors (e.g. https://github.com/open-telemetry/opentelemetry-dotnet/pull/4548/files#r1220139771).

[codecov]

Codecov Report

Merging #4550 (6cfb898) into main (d57e6f8) will increase coverage by 0.00%.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4550   +/-   ##
=======================================
  Coverage   85.11%   85.12%           
=======================================
  Files         320      320           
  Lines       12679    12679           
=======================================
+ Hits        10792    10793    +1     
+ Misses       1887     1886    -1     

see 6 files with indirect coverage changes

[alanwest]

Approving as I'm not actually all that concerned if we always decide to stay on latest DiagnosticSource, but separately, I would like to better understand what is coming in .NET 8 that necessitates a DS version bump.

.NET 8 is improving dependency injection support for Meter/Instrument

It's my understanding that this support may actually be shipped in a new package Microsoft.Extensions.Diagnostics.

I guess the more interesting thing that is coming in DS v8 for our purposes is support for instrumentation scope attributes on Meter. Would be nice to see this for ActivitySource too.

[reyang]

I guess the more interesting thing that is coming in DS v8 for our purposes is support for instrumentation scope attributes on Meter.

Thanks! I agree with what you mentioned here, updated the PR to provider better/accurate examples.

[reyang]

I would like to better understand what is coming in .NET 8 that necessitates a DS version bump.

Here is a subset (scoped to metrics) https://github.com/dotnet/runtime/issues?q=is%3Aopen+label%3Aarea-System.Diagnostics.Metric+milestone%3A8.0.0 FYI @alanwest