chore: add stale bot (#2811)

.github/stale.yml

@@ -0,0 +1,24 @@
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 14
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 7
+# Issues with these labels will never be considered stale
+exemptLabels:
+    - blocked
+    - bug
+    - discussion
+    - enhancement
+    - help-wanted
+    - package-request
+    - pinned
+    - security
+    - upstream
+# Label to use when marking an issue as stale
+staleLabel: stale
+# Comment to post when marking an issue as stale. Set to `false` to disable
+markComment: >
+    This issue has been automatically marked as stale because it has not had
+    recent activity. It will be closed if no further activity occurs. Thank you
+    for your contributions.
+# Comment to post when closing a stale issue. Set to `false` to disable
+closeComment: false