ci: replace issues-helper with stale for inactive check

.github/stale.yml

@@ -0,0 +1,17 @@
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 44
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 7
+# Issues with these labels will never be considered stale
+exemptLabels:
+  - accepted
+  - security
+# Label to use when marking an issue as stale
+staleLabel: 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: true

.github/workflows/issue_check_inactive.yml

@@ -1,17 +0,0 @@
-name: Check inactive
-
-on:
-  schedule:
-    - cron: "0 0 1 * *"
-
-jobs:
-  check-inactive:
-    runs-on: ubuntu-latest
-    steps:
-      - name: check-inactive
-        uses: actions-cool/issues-helper@v3
-        with:
-          actions: 'check-inactive'
-          token: ${{ secrets.GITHUB_TOKEN }}
-          inactive-day: 30
-          body: Hello, this issue has been inactive for more than 30 days and will be closed if inactive for another 30 days.

.github/workflows/issue_close_inactive.yml

@@ -1,21 +0,0 @@
-name: Close inactive
-
-on:
-  schedule:
-    - cron: "0 0 */7 * *"
-  workflow_dispatch:
-
-jobs:
-  close-inactive:
-    runs-on: ubuntu-latest
-    steps:
-      - name: close-issues
-        uses: actions-cool/issues-helper@v3
-        with:
-          actions: 'close-issues'
-          token: ${{ secrets.GITHUB_TOKEN }}
-          labels: 'inactive'
-          inactive-day: 30
-          close-reason: 'not_planned'
-          body: |
-            Hello @${{ github.event.issue.user.login }}, this issue was closed due to inactive more than 60 days. You can reopen or recreate it if you think it should continue.