Update rest-api-spec

Author: github-actions[bot]

output/schema/schema.json

@@ -5,6 +5,10 @@
       "description": "Performs a kNN search."
     },
     "stability": "experimental",
+    "deprecated": {
+      "version": "8.4.0",
+      "description": "The kNN search API has been replaced by the `knn` option in the search API."
+    },
     "visibility": "public",
     "headers": {
       "accept": ["application/json"],

output/schema/validation-errors.json

@@ -11,6 +11,10 @@
     },
     "url": {
       "paths": [
+        {
+          "path": "/_logstash/pipeline",
+          "methods": ["GET"]
+        },
         {
           "path": "/_logstash/pipeline/{id}",
           "methods": ["GET"],