Delete unused .github/stale.yml (#1708)

.github/stale.yml

diff --git a/.github/stale.yml b/.github/stale.yml
deleted file mode 100644
index 1807a00..0000000
--- a/.github/stale.yml
+++ /dev/null
@@ -1,18 +0,0 @@
-# Number of days of inactivity before an issue becomes stale
-daysUntilStale: 365
-# Number of days of inactivity before a stale issue is closed
-daysUntilClose: 30
-# Issues with these labels will never be considered stale
-exemptLabels:
-  - pinned
-  - security
-# 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
-markComment: >
-  This issue has been automatically marked as stale because there has been no
-  activity in the past year.  It will be closed automatically if no further
-  activity occurs in the next 30 days.  Feel free to re-open at any time if this
-  issue is still relevant.
-# Comment to post when closing a stale issue. Set to `false` to disable
-closeComment: false