Update rest-api-spec

Author: pquentin

output/schema/schema.json

@@ -37,12 +37,6 @@
       ],
       "response": []
     },
-    "esql.async_query_get": {
-      "request": [
-        "Request: query parameter 'format' does not exist in the json spec"
-      ],
-      "response": []
-    },
     "get_source": {
       "request": [
         "Request: query parameter 'stored_fields' does not exist in the json spec"

output/schema/validation-errors.json

@@ -24,6 +24,10 @@
       ]
     },
     "params": {
+      "format": {
+        "type": "string",
+        "description": "a short version of the Accept header, e.g. json, yaml"
+      },
       "wait_for_completion_timeout": {
         "type": "time",
         "description": "Specify the time that the request should block waiting for the final response"

specification/_json_spec/esql.async_query_get.json

@@ -7,7 +7,7 @@
     "stability": "experimental",
     "visibility": "public",
     "headers": {
-      "accept": [],
+      "accept": ["application/json"],
       "content_type": ["application/json"]
     },
     "url": {