pass stal bot inactivity limit from 6 to 3 months

Signed-off-by: Guillaume Lours <705411+glours@users.noreply.github.com>

.github/stale.yml

@@ -1,7 +1,7 @@
 # Configuration for probot-stale - https://github.com/probot/stale
 
 # Number of days of inactivity before an Issue or Pull Request becomes stale
-daysUntilStale: 180
+daysUntilStale: 90
 
 # Number of days of inactivity before an Issue or Pull Request with the stale label is closed.
 # Set to false to disable. If disabled, issues still need to be closed manually, but will remain marked as stale.