Project scheduled trigger read failure on Terraform Import

[bec-callow-oct]

Describe the bug
A clear and concise description of what the bug is.

Split from issue #740 as this issue requires an unrelated fix.

The provider cannot find project triggers when attempting to import. It fails with the error

Octopus API error: Resource is not found or it doesn't exist in the current space context. Please contact your administrator for more information. []

When running terraform import, the space ID of the resource is undefined within the resourceProjectScheduledTriggerRead method. We currently use the space ID from the provider as a fallback.

Steps to reproduce

1. Define a scheduled project trigger

   resource "octopusdeploy_project_scheduled_trigger" "foo" {
     name       = "foo"
     project_id = "Projects-2024"
     space_id   = "Spaces-202"
     run_runbook_action {
       runbook_id             = "Runbooks-865"
       target_environment_ids = ["Environments-366"]
     }
     cron_expression_schedule {
       cron_expression = "0 0 * * *" # daily
     }
   }

2. Attempt to import

   terraform import octopusdeploy_project_scheduled_trigger.foo ProjectTriggers-103

3. See error

Expected behavior
A clear and concise description of what you expected to happen.

The provider succeeds in discovering the scheduled project trigger

Logs and other supporting information
Add the output of running tf plan or tf apply along with any errors in the Octopus Server logs.

Planning failed. Terraform encountered an error while generating this plan.

╷
│ Error: Octopus API error: Resource is not found or it doesn't exist in the current space context. Please contact your administrator for more information. []
│
│   with octopusdeploy_project_scheduled_trigger.sandbox_cleanup_report,
│   on projects_administration.tf line 108, in resource "octopusdeploy_project_scheduled_trigger" "sandbox_cleanup_report":
│  108: resource "octopusdeploy_project_scheduled_trigger" "sandbox_cleanup_report" {
│
╵

Screenshots
If applicable, add screenshots to help explain your problem.

N/A

Environment and versions:

• OS: Linux, OSX
• Octopus Server Version: 2024.3.10026
• Terraform Version: 1.8.2
• Octopus Terraform Provider Version: 0.18.1

Additional context
Add any other context about the problem here.

Note copied from issue #740 : It doesn't appear newer versions of the provider have touched this resource but I have not upgraded as the migration to tenant_project resources is a breaking change which is going to require a fair amount of work

[bec-callow-oct]

We should be able to resolve this issue by handling imports in a similar way to how they are handled for environments. This requires us to migrate this resource to use terraform-plugin-framework