matrix: use C locale for the synapse database

Synapse needs the database to be in C locale. Since v1.56.0, it refuses to start when this is not the case, see upgrade.md.

roles/matrix/tasks/main.yml

@@ -172,10 +172,7 @@
     - restart postgres
 
 - name: add synapse postgres db
-  postgresql_db: db=synapse
-  lc_collate: C
-  lc_ctype: C
-  template: template0
+  postgresql_db: db=synapse lc_collate=C lc_ctype=C template=template0
   become: true
   become_user: postgres
   become_method: su