Use C.UTF-8 as the default locale

The glibc 2.35-6 package ships with the C.UTF-8 locale included which means there is now a usable UTF-8 locale available by default.

en_US.UTF-8 will still be generated because PostgreSQL DBs are created with that locale:

• roles/postgres/files/upgrade_pg.sh
• roles/postgres/tasks/main.yml
• roles/postgres/templates/postgresql.conf.j2

playbooks/tasks/sync-ssh-hostkeys.yml

@@ -20,7 +20,7 @@
         | sed 's#^127.0.0.1#{{ inventory_hostname }}#' \
         | sort
       environment:
-        LC_COLLATE: C  # to ensure reproducible ordering
+        LC_COLLATE: C.UTF-8  # to ensure reproducible ordering
       args:
         executable: /bin/bash
       register: known_hosts