Adding github action workflow to mark stale issues and prs. (#62)

* Create stale.yml

Adding github action workflow to mark stale issues and prs.
This stale management workflow will add stale label and post reminder message after 14 days of inactivity and further close issue/pr after another 14 days of inactivity. We can also override stale action by adding override-stale label. Thanks! cc @google/gtech-llm-support

* Update stale.yml

* Update stale.yml

Author: ymodak

.github/workflows/stale.yml

@@ -0,0 +1,49 @@
+# This workflow warns and then closes issues and PRs that have had no activity for a specified amount of time.
+#
+# You can adjust the behavior by modifying this file.
+# For more information, see:
+# https://github.com/actions/stale
+name: Mark stale issues and pull requests
+
+on:
+  schedule:
+  # Scheduled to run at 1.30 UTC everyday
+  - cron: '30 1 * * *'
+
+jobs:
+  stale:
+
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+
+    steps:
+    - uses: actions/stale@v5
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        days-before-issue-stale: 14
+        days-before-issue-close: 14
+        stale-issue-label: "stale"
+        close-issue-reason: completed
+        any-of-labels: "status:awaiting user response,status:more data needed"
+        stale-issue-message: >
+          Marking this issue as stale since it has been open for 14 days with no activity.
+          This issue will be closed if no further activity occurs.
+        close-issue-message: >
+          This issue was closed because it has been inactive for 28 days.
+          Please post a new issue if you need further assistance. Thanks!
+        days-before-pr-stale: 14
+        days-before-pr-close: 14
+        stale-pr-label: "stale"
+        stale-pr-message: >
+          Marking this pull request as stale since it has been open for 14 days with no activity.
+          This PR will be closed if no further activity occurs.
+        close-pr-message: >
+          This pull request was closed because it has been inactive for 28 days.
+          Please open a new pull request if you need further assistance. Thanks!
+        # Label that can be assigned to issues to exclude them from being marked as stale
+        exempt-issue-labels: 'override-stale'
+        # Label that can be assigned to PRs to exclude them from being marked as stale
+        exempt-pr-labels: "override-stale"
+