Remove stale bot and update .asf.yaml settings (#2171)

- Removed stale bot.
  (https://lists.apache.org/thread/qh4h2z6hsjy2v7wg8mwfnl6cbjp28y08)
- Decrease required PR approvals by one.
  (https://lists.apache.org/thread/kmz155t6k0h3b26fjpz36924zthqjlpm)
- Fixed a warning reported by apache infra i.e.
  "An error occurred while processing the github
   feature in .asf.yaml: GitHub discussions can
   only be enabled if a mailing list target exists
   for it."

Author: MuhammadTahaNaveed

.asf.yaml

@@ -19,6 +19,7 @@
 notifications:
     commits:      [email protected]
     pullrequests: [email protected]
+    discussions:  [email protected]
 
 github:
   description: "Graph database optimized for fast analysis and real-time data processing. 
@@ -47,28 +48,28 @@ github:
   protected_branches:
     master:
       required_pull_request_reviews:
-        required_approving_review_count: 2
+        required_approving_review_count: 1
 
     PG16:
       required_pull_request_reviews:
-        required_approving_review_count: 2
+        required_approving_review_count: 1
 
     PG15:
       required_pull_request_reviews:
-        required_approving_review_count: 2
+        required_approving_review_count: 1
 
     PG14:
       required_pull_request_reviews:
-        required_approving_review_count: 2
+        required_approving_review_count: 1
 
     PG13:
       required_pull_request_reviews:
-        required_approving_review_count: 2
+        required_approving_review_count: 1
 
     PG12:
       required_pull_request_reviews:
-        required_approving_review_count: 2
+        required_approving_review_count: 1
 
     PG11:
       required_pull_request_reviews:
-        required_approving_review_count: 2
+        required_approving_review_count: 1