dustin10#1308 Handle empty dimensions array case (dustin10#1309)

When normalizing the File the `getWidth` and `getHeight` are called and while the dimension for null files is returned as an empty array the original check is not enough to handle this case.

src/Entity/File.php

@@ -87,7 +87,7 @@ public function setDimensions(?array $dimensions): void
      */
     public function getWidth(): ?int
     {
-        return null !== $this->dimensions ? $this->dimensions[0] : null;
+        return $this->dimensions[0] ?? null;
     }
 
     /**
@@ -98,7 +98,7 @@ public function getWidth(): ?int
      */
     public function getHeight(): ?int
     {
-        return null !== $this->dimensions ? $this->dimensions[1] : null;
+        return $this->dimensions[1] ?? null;
     }
 
     /**