chore: remove stale action coz it's not keeping issues open after reply

.github/workflows/stale.yml

@@ -1,20 +0,0 @@
-name: "Close stale issues and pull requests"
-on:
-  schedule:
-  - cron: "0 0 * * *"
-
-jobs:
-  stale:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/stale@v1
-      with:
-        repo-token: ${{ secrets.GITHUB_TOKEN }}
-        stale-issue-message: 'Hello 👋, this issue has been open for more than 3 months with no activity on it. If the issue is still present in the latest version, please leave a comment within 7 days to keep it open, otherwise it will be closed automatically. If you found a solution on workaround for the issue, please comment here for others to find. If this issue is critical for you, please consider sending a pull request to fix the issue.'
-        stale-pr-message: 'Hello 👋, this pull request has been open for more than 3 months with no activity on it. If you think this is still necessary with the latest version, please comment and ping a maintainer to get this reviewed, otherwise it will be closed automatically in 7 days.'
-        days-before-stale: 90
-        days-before-close: 7
-        stale-issue-label: 'stale'
-        stale-pr-label: 'stale'
-        exempt-issue-label: 'keep open'
-        exempt-pr-label: 'keep open'