Applied rector suggestions

src/Validator/Constraints/UniqueObjectCollection.php

@@ -1,4 +1,7 @@
 <?php
+
+declare(strict_types=1);
+
 /*
  * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
  *
@@ -17,7 +20,6 @@
  *  You should have received a copy of the GNU Affero General Public License
  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-
 namespace App\Validator\Constraints;
 
 use InvalidArgumentException;
@@ -59,4 +61,4 @@ class UniqueObjectCollection extends Constraint
             throw new InvalidArgumentException(sprintf('The "normalizer" option must be a valid callable ("%s" given).', get_debug_type($this->normalizer)));
         }
     }
-}
+}