Update deploy-pack.yml

Add step to publish the package to the nuget.
see:
ppy/osu-framework@38de9fa

Author: andy840119

.github/workflows/deploy-pack.yml

@@ -67,3 +67,6 @@ jobs:
         with:
           name: osu-framework
           path: ${{steps.artifactsPath.outputs.nuget_artifacts}}\*.nupkg
+
+      - name: Publish packages to nuget.org
+        run: dotnet nuget push ${{steps.artifactsPath.outputs.nuget_artifacts}}/*.nupkg --api-key ${{ secrets.NUGET_AUTH_TOKEN }} --source https://api.nuget.org/v3/index.json