Refactor isRateLimitError function for improved readability

src/install-python.ts

@@ -275,9 +275,7 @@ function sleep(ms: number): Promise<void> {
 // HTTP 403/429 from http-client (`statusCode`) or tool-cache (`httpStatusCode`).
 function isRateLimitError(err: unknown): boolean {
   const e = err as
-    | {httpStatusCode?: number; statusCode?: number}
+    {httpStatusCode?: number; statusCode?: number} | null | undefined;
-    | null
-    | undefined;
   const status = e?.httpStatusCode ?? e?.statusCode;
   return status === 403 || status === 429;
 }