CI Post Release Step Broken

[matrei]

apache/grails-github-actions/post-release@asf errored with:

GIT_USER_NAME: Using default value: sbglasius
Release Version: 6.0.0-RC1
Close Milestone (if it exists)
  Retrieving current milestone number: 
  Closing current milestone
  {
    "message": "Not Found",
    "documentation_url": "https://docs.github.com/rest",
    "status": "404"
  }
Determine next version
  Next version: 6.0.0
Configure Git
  error: insufficient permission for adding an object to repository database .git/objects
  fatal: failed to write object
  fatal: unpack-objects failed

[matrei]

@jdaugherty Is this related to https://github.com/apache/grails-spring-security/pull/1134/files

[sbglasius]

Fixed with the latest grails-release-plugin for Gradle and some adjustments to release.yml