Ansible Automation Platform 2.5 Installer fails with "Upgrades to 2.5 are not currently supported"

Issue

• When trying to upgrade to Ansible Automation Platform 2.5, the installer fails at the following error:

  TASK [ansible.automation_platform_installer.preflight : Preflight check - Fail if this is an attempted upgrade.] 
  fatal: [controller.example.com]: FAILED! => {
   "changed": false,
   "msg": "Upgrades to 2.5 are not currently supported"
  }
  fatal: [automationhub.example.com]: FAILED! => {
   "changed": false,
   "msg": "Upgrades to 2.5 are not currently supported"
  }