Marking ReflectionProperty#$name as string rather than `non-empty…

…-string`

Because @weirdan is a party pooper (they poop at the parties)

Ref: https://www.youtube.com/watch?v=gjwofYhUJEM
Ref: #8722 (comment)

stubs/Reflection.phpstub

@@ -446,7 +446,7 @@ class ReflectionFunction extends ReflectionFunctionAbstract
 class ReflectionProperty implements Reflector
 {
     /**
-     * @var non-empty-string
+     * @var string
      * @readonly
      */
     public $name;