Various update meta-data in files.

app/Models/UserGroup.php

@@ -1,4 +1,5 @@
 <?php
+
 /*
  * UserGroup.php
  * Copyright (c) 2021 james@firefly-iii.org
@@ -19,6 +20,8 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+declare(strict_types=1);
+
 namespace FireflyIII\Models;
 
 use Illuminate\Database\Eloquent\Model;
@@ -40,4 +43,4 @@ class UserGroup extends Model
     {
         return $this->hasMany(GroupMembership::class);
     }
-}
+}