ci: remove Stalebot (#26)

.github/workflows/stale.yml

@@ -1,46 +0,0 @@
-name: Stale
-
-on:
-  schedule:
-    - cron: '0 12 * * *'
-
-jobs:
-  analyze:
-    name: Analyze
-    runs-on: ubuntu-latest
-
-    strategy:
-      fail-fast: false
-      matrix:
-        language: ['python']
-
-    steps:
-      - name: Close Stale Issues
-        uses: actions/stale@v3
-        with:
-          start-date: 2021-02-01
-
-          days-before-stale: 60
-          days-before-issue-close: 7
-          days-before-pr-close: 14
-
-          stale-label: stale
-          close-issue-label: wontfix
-          close-pr-label: wontmerge
-
-          exempt-issue-label: 'confirmed,enhancement'
-          exempt-pr-label: 'on hold'
-
-          stale-issue-message: >
-            This issue has not been active since a lot of time. If you think it is still valid, feel free to reply with a simple comment.
-            Without any update, I will close it in 7 days.
-          stale-pr-message: >
-            This pull request has not been active since a lot of time. If you're still working on it, please reply with a simple comment.
-            Without any update, I will close it in 14 days.
-
-          close-issue-message: >
-            Closing this issue.
-            If you think it should be considered, feel free to exhume it.
-          close-pr-message: >
-            Closing this PR, since it has not got activity for a while.
-            If you're still working on it, feel free to reopen it.