Add workflows to OPA custom policies

[Shnitselon]

We are excited to announce support for workflows in OPA custom policies, allowing you to run workflows as part of your custom policies. With this feature, you can automate complex tasks and enforce policy requirements across your entire environment. For example, if an end-user launches an environment and needs it to run 24 hours a day, they can request to disable the scheduled workflow that turns off VMs at the end of the workday, and the request will be sent to the approval engine for review. For details, see Custom Policies.