Pull request: imp-stalebot

Merge in DNS/adguard-home from imp-stalebot to master

Squashed commit of the following:

commit d1fb5c6da25eeb168c53abfc7af714827a5242cd
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Sep 21 14:31:50 2022 +0300

    all: imp stalebot

.github/stale.yml

@@ -13,6 +13,8 @@
   - 'needs investigation'
   - 'recurrent'
   - 'research'
+# Set to true to ignore issues in a milestone.
+'exemptMilestones': true
 # Label to use when marking an issue as stale.
 'staleLabel': 'wontfix'
 # Comment to post when marking an issue as stale. Set to `false` to disable.
@@ -22,3 +24,5 @@
   for your contributions.
 # Comment to post when closing a stale issue. Set to `false` to disable.
 'closeComment': false
+# Limit the number of actions per hour.
+'limitPerRun': 1