nixos: services: nextcloud: simplify DB handling

I *think* the option didn't exist when I originally used this module.

modules/nixos/services/nextcloud/default.nix

@@ -44,11 +44,15 @@ in
         adminuser = cfg.admin;
         adminpassFile = cfg.passwordFile;
         dbtype = "pgsql";
-        dbhost = "/run/postgresql";
       };
 
       https = true;
 
+      # Automatic PostgreSQL provisioning
+      database = {
+        createLocally = true;
+      };
+
       settings = {
         overwriteprotocol = "https"; # Nginx only allows SSL
       };
@@ -60,22 +64,6 @@ in
       };
     };
 
-    services.postgresql = {
-      enable = true;
-      ensureDatabases = [ "nextcloud" ];
-      ensureUsers = [
-        {
-          name = "nextcloud";
-          ensureDBOwnership = true;
-        }
-      ];
-    };
-
-    systemd.services."nextcloud-setup" = {
-      requires = [ "postgresql.service" ];
-      after = [ "postgresql.service" ];
-    };
-
     # The service above configures the domain, no need for my wrapper
     services.nginx.virtualHosts."nextcloud.${config.networking.domain}" = {
       forceSSL = true;