chore: replace stale workflow with probot

.github/stale.yml

@@ -0,0 +1,19 @@
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 20
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 5
+# Issues with these labels will never be considered stale
+exemptLabels:
+  - pinned
+  - security
+  - 'status: pinned'
+  - 'type: security'
+# Label to use when marking an issue as stale
+staleLabel: 'status: stale'
+# Comment to post when marking an issue as stale. Set to `false` to disable
+markComment: >
+  This issue has been automatically marked as stale because it has not had
+  recent activity. It will be closed if no further activity occurs. Thank you
+  for your contributions.
+# Comment to post when closing a stale issue. Set to `false` to disable
+closeComment: false

.github/workflows/stale.yml

@@ -1,21 +0,0 @@
-name: 'Handle stale issues and PRs'
-on:
-  schedule:
-    - cron: '0 0 * * *'
-  workflow_dispatch:
-
-jobs:
-  stale:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/stale@v3
-        with:
-          repo-token: ${{ secrets.GITHUB_TOKEN }}
-          stale-issue-message: 'This issue is being marked as "stale" because it has been open 20 days with no activity. Remove the "stale" label or comment, otherwise this will be closed in 5 days.'
-          stale-issue-label: 'status: stale'
-          exempt-issue-labels: 'status: pinned'
-          stale-pr-message: 'This PR is being marked as "stale" because it has been open 20 days with no activity. Remove the "stale" label or comment, otherwise this will be closed in 5 days.'
-          stale-pr-label: 'status: stale'
-          exempt-pr-labels: 'status: pinned'
-          days-before-stale: 20
-          days-before-close: 5