Update lock bot config

Author: iansu

.github/lock.yml

@@ -3,6 +3,9 @@
 # Number of days of inactivity before a closed issue or pull request is locked
 daysUntilLock: 5
 
+# Issues and pull requests with these labels will not be locked. Set to `[]` to disable
+exemptLabels: []
+
 # Do not comment when locking
 setLockReason: false
 lockComment: false