Add Xbox UWP build workflow

src/update/Check.lua

@@ -17,6 +17,7 @@
 -- worker can reuse the exact same code path via love.filesystem.load.
 
 local Check = {}
+local Platform = require("src.core.Platform")
 
 Check.REPO = "bryanthaboi/gen1recomp"
 
@@ -99,8 +100,7 @@ local cache = { status = "idle" } -- newest snapshot from the worker
 
 local function ensureWorker()
   if workerReady ~= nil then return workerReady end
-  if love and love.system and love.system.getOS
-      and love.system.getOS() == "UWP" then
+  if not Platform.networkValidated() then
     workerReady = false
     return false
   end