Transition to GitHub App auth, remove azuresdk-github-pat usage (#2473)

Related to Azure/azure-sdk-tools#9842

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: scbedd

eng/pipelines/templates/stages/archetype-ios-release.yml

@@ -57,6 +57,7 @@ stages:
                   ArtifactLocation: $(System.DefaultWorkingDirectory)/sdk/${{parameters.ServiceDirectory}}/${{artifact.name}}
                   PackageRepository: CocoaPods
                   ReleaseSha: $(Build.SourceVersion)
+                  AuthToken: ''
 
           - ${{if ne(artifact.skipCocoaPods, 'true')}}:
             - job: PublishPackageToCocoaPodsTrunk