Change Milky Way author's pseudonym to "ruvkr"

The author contacted me and requested that their pseudonym be changed
from "Metal Bender" to "ruvkr", which is their GitHub username.

The SVG source file for the wallpaper can be found at
https://github.com/ruvkr/milkyway

wallpapers/Next/metadata.desktop

@@ -13,6 +13,6 @@ Name[uk]=Чумацький Шлях
 Name[x-test]=xxMilky Wayxx
 
 X-KDE-PluginInfo-Name=Next
-X-KDE-PluginInfo-Author=Metal Bender
+X-KDE-PluginInfo-Author=ruvkr
 X-KDE-PluginInfo-Email=universalemail.gm@gmail.com
 X-KDE-PluginInfo-License=CC-BY-SA-4.0