docs: change from detecting version to since tag (#13127)

* update everything from version to since

* update events

* regenerate oas

www/packages/types/src/openapi.ts

@@ -23,7 +23,7 @@ export type Operation = OpenAPIV3.OperationObject<{
   "x-workflow"?: string
   "x-sidebar-summary"?: string
   "x-events"?: OasEvents[]
-  "x-version"?: string
+  "x-since"?: string
   "x-deprecated_message"?: string
   "x-badges"?: {
     text: string
@@ -149,5 +149,5 @@ export type OasEvents = {
   description?: string
   deprecated?: boolean
   deprecated_message?: string
-  version?: string
+  since?: string
 }