Remove duplicate publish task for NuGet artifacts in release.yml

[Copilot]

The release pipeline contained two PublishBuildArtifacts@1 tasks that were redundantly publishing NuGet packages:

1. First task: Published all build artifacts from $(Build.ArtifactStagingDirectory) as 'FhirAnonymizerBuild'
2. Second task: Published only NuGet packages from $(build.artifactStagingDirectory)/nupkgs as 'nuget'

The second task was redundant because:

• The first publish task already includes ALL artifacts, including NuGet packages stored in the /nupkgs subdirectory
• The Release stage only downloads and uses the 'FhirAnonymizerBuild' artifact
• No other files in the codebase reference the separate 'nuget' artifact
• Codebase search confirmed the 'nuget' artifact name only appears in release.yml

This appears to be legacy code from when there may have been separate processes that consumed only the NuGet packages. The removal simplifies the pipeline while maintaining all required functionality.

Changes:

• Removed the duplicate publish task for NuGet artifacts (lines 103-108)
• Updated display name from 'publish binary artifacts' to 'publish build artifacts' for clarity
• Verified YAML syntax validity and confirmed builds still work correctly

Fixes #260.

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[chrisribe]

@josiahvinson was not sure about this as this is part of legacy and there could be an underlying reason we do this.