Add workflow to manage stale PRs

.github/workflows/stale-backtrace-issues.yml

@@ -0,0 +1,17 @@
+name: 'Manage stale backtrace reports'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v7
+        with:
+          days-before-issue-stale: 60
+          days-before-issue-close: 1
+          only-issue-labels: 'backtrace.io'
+          stale-issue-label: 'stale-backtrace'
+          stale-pr-message: 'This issue is stale and will be closed tomorrow if no action is taken. To keep it open, leave a comment or remove the `stale-backtrace` label.'
+          close-pr-message: 'This issue was closed due to inactivity.'

.github/workflows/stale-prs.yml

@@ -0,0 +1,16 @@
+name: 'Manage stale PRs'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v7
+        with:
+          days-before-pr-stale: 14
+          days-before-pr-close: 14
+          stale-pr-label: 'stale-pr'
+          stale-pr-message: 'This pull request is stale and will be closed in 14 days if no action is taken. To keep it open, leave a comment or remove the `stale-pr` label. If you''re awaiting feedback from a developer, please send us a reminder (either here or on [Discord](https://discord.gg/ZXZd8D8)).'
+          close-pr-message: 'This pull request was closed due to inactivity.'