fix yaml archives for conformance

[theganyo]

Fixes #1203

• Use Artifact id for conformance workers instead of stylesheet id
• Simplify artifact patching behavior
• Remove unnecessary structure test

[codecov]

Codecov Report

❌ Patch coverage is 68.18182% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.91%. Comparing base (76ddac3) to head (06653c8).
⚠️ Report is 11 commits behind head on main.

Files with missing lines	Patch %	Lines
cmd/registry/patch/artifact.go	76.47%	3 Missing and 1 partial ⚠️
...md/registry/cmd/compute/conformance/conformance.go	40.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1206      +/-   ##
==========================================
- Coverage   71.96%   71.91%   -0.06%     
==========================================
  Files         146      146              
  Lines       12241    12208      -33     
==========================================
- Hits         8809     8779      -30     
+ Misses       2749     2747       -2     
+ Partials      683      682       -1     

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[timburks]

I think this will break API hub, which currently reads proto-serialized artifacts and expects them to contain "kind" and "id" fields. Since these fields are redundant in Registry YAML, I don't think we should be including them in YAML-serialized artifacts and I expect that API hub will adapt to that when it starts reading those YAML-serialized artifacts.

[theganyo]

That's unfortunate. So I need to add this back for protos?

[theganyo]

Actually, this PR isn't critical until we go all in on yaml...perhaps we should hold it until we correct API Hub.