Rename SettingUp to Preparing in ScenarioRunState enum (#42780)

Renames the SettingUp enum value to Preparing in the ScenarioRunState
union for a more generalized lifecycle phase name.

Co-authored-by: Shankar Daruga <sdaruga@microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 3 people

specification/chaos/resource-manager/Microsoft.Chaos/Chaos/preview/2026-05-01-preview/openapi.json

@@ -6745,7 +6745,7 @@
         "Validating",
         "ValidationSucceeded",
         "Starting",
-        "SettingUp",
+        "Preparing",
         "Running",
         "CleaningUp",
         "Canceling",
@@ -6788,9 +6788,9 @@
             "description": "The scenario run is in the process of being started."
           },
           {
-            "name": "SettingUp",
-            "value": "SettingUp",
-            "description": "The scenario run is in the process of being setup."
+            "name": "Preparing",
+            "value": "Preparing",
+            "description": "The scenario run is in the process of being prepared."
           },
           {
             "name": "Running",

specification/chaos/resource-manager/Microsoft.Chaos/Chaos/scenarioRun.models.tsp

@@ -344,9 +344,9 @@ union ScenarioRunState {
   Starting: "Starting",
 
   /**
-   * The scenario run is in the process of being setup.
+   * The scenario run is in the process of being prepared.
    */
-  SettingUp: "SettingUp",
+  Preparing: "Preparing",
 
   /**
    * The scenario run is in the process of running.