Revert to API-key NuGet publish (#391)

NuGet/login (Trusted Publishing) is not on the org's GitHub Actions
allowlist, so the OIDC publish fails at startup. Revert to the
allowlisted aws-actions flow that reads the NuGet API key from AWS
Secrets Manager. The stored key must be refreshed for publishing to
succeed.

Automated Spec Update 06/30/2026 and upgrade CI to .NET 8 LTS (#375)

7.0.0 release

6.37.0 release

6.36.0 release

6.35.0 release

6.34.0 release

6.33.0 release

6.32.0 release

6.31.0 release