Add missing Grafana_Update LRO header to Microsoft.Dashboard 2024-11-01-preview and update TypeSpec spec (Azure#35849)

* add missing lro header + change tsp to async

* run tsp compile . for swagger

Author: joshelton1

specification/dashboard/Dashboard.Management/ManagedGrafana.tsp

@@ -64,10 +64,11 @@ interface ManagedGrafanas {
   #suppress "@azure-tools/typespec-azure-resource-manager/no-response-body" "FIXME: Update justification, follow aka.ms/tsp/conversion-fix for details"
   @patch(#{ implicitOptionality: false })
   @operationId("Grafana_Update")
-  update is ArmCustomPatchSync<
+  update is ArmCustomPatchAsync<
     ManagedGrafana,
     PatchModel = ManagedGrafanaUpdateParameters,
-    Response = ArmResponse<ManagedGrafana> | (AcceptedResponse & {
+    Response = ArmResponse<ManagedGrafana> | (ArmAcceptedLroResponse<LroHeaders = ArmAsyncOperationHeader<FinalResult = ManagedGrafana> &
+      Azure.Core.Foundations.RetryAfterHeader> & {
       @bodyRoot
       _: ManagedGrafana;
     })

specification/dashboard/resource-manager/Microsoft.Dashboard/preview/2024-11-01-preview/grafana.json

@@ -647,6 +647,17 @@
             "description": "The request has been accepted for processing, but processing has not yet completed.",
             "schema": {
               "$ref": "#/definitions/ManagedGrafana"
+            },
+            "headers": {
+              "Azure-AsyncOperation": {
+                "type": "string",
+                "description": "A link to the status monitor"
+              },
+              "Retry-After": {
+                "type": "integer",
+                "format": "int32",
+                "description": "The Retry-After header can indicate how long the client should wait before polling the operation status."
+              }
             }
           },
           "default": {
@@ -660,7 +671,11 @@
           "Grafana_Update": {
             "$ref": "./examples/Grafana_Update.json"
           }
-        }
+        },
+        "x-ms-long-running-operation-options": {
+          "final-state-via": "azure-async-operation"
+        },
+        "x-ms-long-running-operation": true
       },
       "delete": {
         "operationId": "Grafana_Delete",