Update GitHub Actions Guide to use OIDC auth instead of AZURE_CREDENTIALS

[AaronCrawfis]

This page: https://docs.radapp.io/guides/deploy-apps/howto-deploy/howto-deploy-cicd/ should be updated to use managed identities/OIDC instead of AZURE_CREDENTIALS and client secrets. See this guide for more information: https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/configuring-openid-connect-in-azure

AB#11515