test: satisfy phpstan (#284)

Author: priyadi

src/Transformer/Implementation/TraversableToArrayAccessTransformer.php

@@ -199,6 +199,7 @@ private function eagerTransform(
                         $target[] = $value;
                     }
                 } else {
+                    // @phpstan-ignore offsetAccess.invalidOffset
                     $target[$key] = $value;
                 }
 
@@ -226,6 +227,7 @@ private function eagerTransform(
             } else {
                 foreach ($target as $key => $value) {
                     if (!\in_array($value, $values, true)) {
+                        // @phpstan-ignore offsetAccess.invalidOffset
                         unset($target[$key]);
                     }
                 }

src/Transformer/Trait/ArrayLikeTransformerTrait.php

@@ -215,6 +215,7 @@ private function transformMember(
                  * @var mixed
                  * @psalm-suppress MixedArrayOffset
                  * @psalm-suppress MixedArrayTypeCoercion
+                 * @phpstan-ignore offsetAccess.invalidOffset
                  */
                 $targetMemberValue = $target[$targetMemberKey] ?? null;
             } else {