Fix handwired/promethium keyboard dimensions in info.json

keyboards/handwired/promethium/info.json

@@ -3,7 +3,7 @@
   "url": "",
   "maintainer": "qmk",
   "width": 16,
-  "height": 5,
+  "height": 4.5,
   "layouts": {
     "LAYOUT": {
       "layout": [