remove deprecated postgresql config

https://pgpedia.info/s/stats_temp_directory.html
> From PostgreSQL 15, temporary statistics are stored in memory by default so stats_temp_directory will no longer be available.

roles/postgresql/tasks/main.yml

@@ -21,14 +21,6 @@
   notify:
     - restart postgresql
 
-- name: Prevent disk writes when idle
-  lineinfile: dest={{ postgresql.root }}/data/postgresql.conf
-              regexp=^stats_temp_directory
-              state=present
-              line="stats_temp_directory = '/run/postgresql'"
-  notify:
-    - restart postgresql
-
 - name: Create service override directory
   file: path=/etc/systemd/system/postgresql.service.d state=directory