chore: add GitHub workflow to close stale PRs (#10046)

* Add action to close stale issues and PRs

* add notes to contributors guide

* prettier

* Update .github/workflows/stale.yml

Co-authored-by: Andrew Lamb <[email protected]>

* do not close stale issues

* update docs

* prettier

---------

Co-authored-by: Andrew Lamb <[email protected]>

.github/workflows/stale.yml

@@ -0,0 +1,38 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+name: "Close stale PRs"
+on:
+  schedule:
+    - cron: "30 1 * * *"
+
+jobs:
+  close-stale-prs:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+      - uses: actions/stale@v9
+        with:
+          stale-pr-message: "Thank you for your contribution. Unfortunately, this pull request is stale because it has been open 60 days with no activity. Please remove the stale label or comment or this will be closed in 7 days."
+          days-before-pr-stale: 60
+          days-before-pr-close: 7
+          # do not close stale issues
+          days-before-issue-stale: -1
+          days-before-issue-close: -1
+          repo-token: ${{ secrets.GITHUB_TOKEN }}

docs/source/contributor-guide/index.md

@@ -106,6 +106,11 @@ A "major" PR means there is a substantial change in design or a change in the AP
 
 The good thing about open code and open development is that any issues in one change can almost always be fixed with a follow on PR.
 
+## Stale PRs
+
+Pull requests will be marked with a `stale` label after 60 days of inactivity and then closed 7 days after that.
+Commenting on the PR will remove the `stale` label.
+
 ## Getting Started
 
 This section describes how you can get started at developing DataFusion.