[lib] Set failedQueryCacheTimeout to 0 in UserIdentityCache

Summary: This addresses [ENG-9255](https://linear.app/comm/issue/ENG-9255/reduce-failedquerycachetimeout-in-useridentitycache), and makes it so if a user identity fetch times out, the next time it's requested, we don't return `null` from the cache, but instead retry the fetch.

Test Plan: I set `queryTimeout` to 1 second, which made it time out. I confirmed in the logs that after the timeout, a second request was dispatched

Reviewers: varun, will

Reviewed By: varun

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D13299

lib/components/user-identity-cache.react.js

@@ -11,7 +11,9 @@ import type {
 import sleep from '../utils/sleep.js';
 
 const cacheTimeout = 24 * 60 * 60 * 1000; // one day
-const failedQueryCacheTimeout = 5 * 60 * 1000; // five minutes
+// If the query fails due to a timeout, we don't cache it
+// This forces a retry on the next request
+const failedQueryCacheTimeout = 0;
 const queryTimeout = 20 * 1000; // twenty seconds
 
 async function throwOnTimeout(identifier: string) {
@@ -172,7 +174,7 @@ function UserIdentityCacheProvider(props: Props): React.Node {
             });
             continue;
           }
-          resultMap.set(userID, null);
+          resultMap.set(userID, undefined);
         }
         return resultMap;
       })();