Remove experiment status from work items GraphQL API

Now that we're getting to GA of work items, we should start removing the isDeprecated tags from the GraphQL API that we were using to mark the experimental status. This is a list of the APIs that need to be updated:

• Queries

  • workItem
  • workItemsByReference

• Mutations

  • workItemAddClosingMergeRequest
  • workItemAddLinkedItems
  • workItemBulkUpdate
  • workItemConvert
  • workItemCreate
  • workItemCreateFromTask
  • workItemDelete
  • workItemExport
  • workItemRemoveLinkedItems
  • workItemSubscribe
  • workItemUpdate
  • workItemsHierarchyReorder

• Types

  • WorkItem
  • WorkItemDeletePayload
  • WorkItemType
  • WorkItemWidgetAssignees
  • WorkItemWidgetHealthStatus
  • WorkItemWidgetHierarchy
  • WorkItemWidgetLabels
  • WorkItemWidgetLinkedItems
  • WorkItemWidgetRequirementLegacy
  • WorkItemWidgetWeight