[8.11] [OAS] Migrate machine learning APIs to v3.1.0 (#171594) (#171889)

# Backport

This will backport the following commits from `main` to `8.11`:
- [[OAS] Migrate machine learning APIs to v3.1.0
(#171594)](https://github.com/elastic/kibana/pull/171594)

<!--- Backport version: 8.9.8 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Lisa
Cawley","email":"lcawley@elastic.co"},"sourceCommit":{"committedDate":"2023-11-23T19:46:05Z","message":"[OAS]
Migrate machine learning APIs to v3.1.0
(#171594)","sha":"2f258a229c702fa10a58cbcf7baec7917d64c83c","branchLabelMapping":{"^v8.12.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["release_note:skip","docs","backport:prev-minor","v8.12.0"],"number":171594,"url":"https://github.com/elastic/kibana/pull/171594","mergeCommit":{"message":"[OAS]
Migrate machine learning APIs to v3.1.0
(#171594)","sha":"2f258a229c702fa10a58cbcf7baec7917d64c83c"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v8.12.0","labelRegex":"^v8.12.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/171594","number":171594,"mergeCommit":{"message":"[OAS]
Migrate machine learning APIs to v3.1.0
(#171594)","sha":"2f258a229c702fa10a58cbcf7baec7917d64c83c"}}]}]
BACKPORT-->

x-pack/plugins/ml/common/openapi/ml_apis_v3.yaml

@@ -1,8 +1,8 @@
-openapi: 3.0.1
+openapi: 3.1.0
 info:
   title: Machine learning APIs
   description: Kibana APIs for the machine learning feature
-  version: "1.0.1"
+  version: "1.0.2"
   license:
     name: Elastic License 2.0
     url: https://www.elastic.co/licensing/elastic-license
@@ -56,7 +56,8 @@ components:
     required: false
     schema:
       type: boolean
-    example: 'true'
+      examples:
+        - true
  securitySchemes:
   basicAuth:
     type: http
@@ -161,12 +162,14 @@ components:
       properties:
         error:
           type: string
-          example: Unauthorized
+          examples:
+            - Unauthorized
         message:
           type: string 
         statusCode:
           type: integer
-          example: 401
+          examples:
+            - 401
  examples:
    mlSyncExample:
      summary: Two anomaly detection jobs required synchronization in this example.