Added declare strict types to all files

src/Entity/Parts/Part.php

@@ -147,7 +147,7 @@ class Part extends AttachmentContainingDBElement
         //Ensure that the part name fullfills the regex of the category
         if ($this->category instanceof Category) {
             $regex = $this->category->getPartnameRegex();
-            if (!empty($regex) && !preg_match($regex, $this->name)) {
+            if ($regex !== '' && !preg_match($regex, $this->name)) {
                 $context->buildViolation('part.name.must_match_category_regex')
                     ->atPath('name')
                     ->setParameter('%regex%', $regex)

src/Entity/Parts/PartTraits/ProjectTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace App\Entity\Parts\PartTraits;
 
 use App\Entity\ProjectSystem\Project;
@@ -81,4 +83,4 @@ trait ProjectTrait
 
         return $projects;
     }
-}
+}