chore(backend): Warn about backend api return format deprecation

Currently the return value is the response.body `data` or
 throws a ClerkAPIResponseError error with the response.body `errors`

Author: dimkl

packages/backend/src/api/request.ts

@@ -51,6 +51,11 @@ type LegacyRequestFunction = <T>(requestOptions: ClerkBackendApiRequestOptions)
 const withLegacyReturn =
   (cb: any): LegacyRequestFunction =>
   async (...args) => {
+    deprecated(
+      '',
+      'Resources return format will switch to `{ data: any, errors: ClerkAPIError[] }` from `data | never` the next major version.',
+      'resources-legacy-return',
+    );
     // @ts-ignore
     const { data, errors, status, statusText } = await cb<T>(...args);
     if (errors === null) {