PHPCS and PHStan appeasement

tests/PhpSpreadsheetTests/Cell/AdvancedValueBinderTest.php

@@ -43,7 +43,7 @@ class AdvancedValueBinderTest extends TestCase
         StringHelper::setThousandsSeparator($this->thousandsSeparator);
     }
 
-    public function testNullValue()
+    public function testNullValue(): void
     {
         /** @var Cell&MockObject $cellStub */
         $cellStub = $this->getMockBuilder(Cell::class)

tests/data/Cell/DefaultValueBinder.php

@@ -80,5 +80,5 @@ return [
     'Numeric that exceeds PHP MAX_INT Size' => [
         's',
         '1234567890123459012345689012345690',
-    ]
+    ],
 ];