ci: simplify GitHub Packages push authentication

Use --api-key flag directly instead of adding a named source,
reducing complexity and potential credential storage issues.

🤖 Generated with [opencode](https://opencode.ai)

Co-Authored-By: opencode <noreply@opencode.ai>

Author: StevenTCramer

.github/workflows/ci-cd.yml

@@ -48,11 +48,7 @@ jobs:
       - name: Publish to GitHub Packages
         if: github.event_name == 'release' || github.event_name == 'workflow_dispatch'
         run: |
-          dotnet nuget add source \
-            --username ${{ github.actor }} \
-            --password ${{ secrets.GITHUB_TOKEN }} \
-            --store-password-in-clear-text \
-            --name github \
-            "https://nuget.pkg.github.com/TimeWarpEngineering/index.json"
-          
-          dotnet nuget push artifacts/packages/*.nupkg --source "github" --skip-duplicate
+          dotnet nuget push artifacts/packages/*.nupkg \
+            --source "https://nuget.pkg.github.com/TimeWarpEngineering/index.json" \
+            --api-key ${{ secrets.GITHUB_TOKEN }} \
+            --skip-duplicate