Stale issues more frequently (4 times a day) (#36130)

Summary:
Our stale bot is at capacity and reaches quota, resulting in marking as stale 2/3 issues a day.
I'm increasing the frequency of the bot to 4 times a day.

## Changelog

Changelog:
[Internal] [Changed] - Stale issues more frequently (4 times a day)

Pull Request resolved: https://github.com/facebook/react-native/pull/36130

Test Plan: nothing to test

Reviewed By: cipolleschi

Differential Revision: D43207979

Pulled By: cortinico

fbshipit-source-id: 1de45315e724ddf9afdb9426eddc639875ba0b24

.github/workflows/stale-bot.yml

@@ -1,7 +1,7 @@
 name: Mark stale issues and pull requests
 on:
   schedule:
-    - cron: "30 1 * * *"
+    - cron: "0 0,6,12,18 * * *"
 jobs:
   stale:
     runs-on: ubuntu-latest