Fix name file preference for PGDG repository

postgresql/tasks/pgdg-repo.yml

@@ -21,5 +21,5 @@
 - name: Add APT preference file
   template:
     src: postgresql.pref.j2
-    dest: /etc/apt/preferences.d/
+    dest: /etc/apt/preferences.d/postgresql.pref
     mode: "0644"