Fun with output variables

Octopus 2.4 introduces a feature that allows variables from one deployment step to be available in subsequent steps, enhancing the flexibility and efficiency of deployment processes. This is accomplished through output variables, which can be created using the `Set-OctopusVariable` command and are stored after each step for later use. In addition to user-defined variables, Octopus provides built-in output variables for tasks like NuGet package deployments and manual interventions, offering details such as installation directory paths and user information. The system operates across multiple machines simultaneously, meaning each machine can produce different values for the same output variable, which are then scoped to individual machines. For broader access, Octopus also indexes variables by machine, allowing steps running on different machines to retrieve values produced elsewhere. This functionality is particularly useful for tasks like determining previous package installation paths, as Octopus extracts packages to new directories by default to prevent issues. The integration of output variables streamlines the deployment process by facilitating the sharing of values across steps and machines, making it a powerful tool for managing complex deployments in Octopus.