Pull requests in Azure DevOps Services are blocked by checks waiting on status updates from runs in Terraform Cloud/Enterprise workspaces which have been deleted.
This can be caused by branch policies on the Azure DevOps Services repository. Branch policies are used to enforce certain workflows for one or more branches. These policies can require status checks, such as speculative plans in Terraform Cloud/Enterprise, pass before a pull request to the branch is able to be merged. While the workspace referenced in the status check may no longer exist in Terraform Cloud/Enterprise, the repository branch may still be configured to require a passing update from it as a part of its branch policies.
Navigate to the project in Azure DevOps Services and, under Repos -> Branches, find the target branch of the pull request. Select More options -> Branch policies and, under Status Checks, find the rule which references the deleted Terraform Cloud/Enterprise workspace and remove it.
If you continue to experience issues, please contact HashiCorp Support.