Add stale/lock bots (#2299)

.github/workflows/lock.yml

@@ -0,0 +1,21 @@
+name: Lock
+
+on:
+  schedule:
+    - cron: "0 * * * *"
+  workflow_dispatch:
+
+permissions:
+  issues: write
+  pull-requests: write
+
+jobs:
+  lock:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: dessant/lock-threads@v2
+        with:
+          github-token: ${{ github.token }}
+          pr-lock-inactive-days: "1"
+          pr-lock-reason: ""
+          process-only: prs

.github/workflows/stale.yml

@@ -0,0 +1,30 @@
+name: Stale
+
+on:
+  schedule:
+    - cron: "0 * * * *"
+  workflow_dispatch:
+
+permissions:
+  issues: write
+  pull-requests: write
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v4
+        with:
+          repo-token: ${{ github.token }}
+          days-before-pr-stale: 90
+          days-before-pr-close: 7
+          days-before-issue-stale: -1
+          days-before-issue-close: -1
+          remove-stale-when-updated: true
+          stale-pr-label: "stale"
+          exempt-pr-labels: "no-stale"
+          stale-pr-message: >
+            There hasn't been any activity on this pull request recently. This
+            pull request has been automatically marked as stale because of that
+            and will be closed if no further activity occurs within 7 days.
+            Thank you for your contributions.