fix(identity-kubernetes-auth): update error handling for token review requests

- Replaced UnauthorizedError with BadRequestError in handleAxiosHttpError for improved clarity in error reporting related to token review requests.

backend/src/services/identity-kubernetes-auth/identity-kubernetes-auth-error-handlers.ts

@@ -139,7 +139,7 @@ export const handleAxiosHttpError = (
   }
 
   if (message) {
-    return new UnauthorizedError({
+    return new BadRequestError({
       message,
       name: `${prefix}TokenReviewRequestError`
     });