chore: add lock and stale config (#4240)

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.github/lock.yml

@@ -0,0 +1,8 @@
+# Configuration for lock-threads - https://github.com/dessant/lock-threads
+daysUntilLock: 30
+exemptLabels: []
+lockLabel: false
+lockComment: >
+  This thread has been automatically locked since there has not been
+  any recent activity after it was closed. Please open a new issue for
+  related bugs.

.github/stale.yml

@@ -0,0 +1,7 @@
+# Configuration for probot-stale - https://github.com/probot/stale
+daysUntilStale: 21
+daysUntilClose: 7
+staleLabel: stale
+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.