Set name argument type

Co-authored-by: Progi1984 <progi1984@gmail.com>

Author: radarhere

src/PhpWord/Shared/XMLWriter.php

@@ -173,7 +173,7 @@ public function writeAttributeIf($condition, $attribute, $value): void
      * @param string $name
      * @param mixed $value
      */
-    public function writeAttribute($name, $value): bool
+    public function writeAttribute(string $name, $value): bool
     {
         if (is_float($value)) {
             $value = json_encode($value);