Add GCP Cloud Run resource attributes

[damemi]

This adds the new attributes from open-telemetry/opentelemetry-specification#3378 to the Go semconv

[codecov]

Codecov Report

Merging #4079 (f1fca8a) into main (6f04547) will decrease coverage by 0.1%.
The diff coverage is n/a.

❗ Current head f1fca8a differs from pull request most recent head d003b70. Consider uploading reports for the commit d003b70 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #4079     +/-   ##
=======================================
- Coverage   82.8%   82.8%   -0.1%     
=======================================
  Files        177     177             
  Lines      13494   13494             
=======================================
- Hits       11176   11174      -2     
- Misses      2097    2099      +2     
  Partials     221     221             

see 1 file with indirect coverage changes

[MadVikingGod]

If you look at the very top of this file, you will see this is a generated file.

This doesn't do the needed work to add parsing into the tooling to generate these attributes from the actual source.

[damemi]

@MadVikingGod yeah sorry, I noticed that after I opened this. Switched it to a draft just so I have a placeholder but I can close it if that's easier.

Will these new resources just be automatically pulled in with the next release? Or will I need to open a PR to generate the files?

(btw, I checked a couple of the readmes and contributing files and it wasn't obvious to me what the workflow for updating these is)

[damemi]

Closing, asked about this in the sig meeting and it looks like my changes will be in the 1.21 release