fixed file name for serverless persistent store

utils/odAuthTokenStore.ts

@@ -1,11 +1,14 @@
 // This should be only used on the server side, where the tokens are stored with KV store using
 // a file system based storage. The tokens are stored in the file system as JSON at /tmp path.
+import os from 'os'
 
 import Keyv from 'keyv'
 import { KeyvFile } from 'keyv-file'
 
 const kv = new Keyv({
-  store: new KeyvFile(),
+  store: new KeyvFile({
+    filename: `${os.tmpdir()}/od-auth-token.json`,
+  }),
 })
 
 export async function storeOdAuthTokens({