I have the same issue. I’ve previously had a similar issue with entitlements for a 3rd party SDK, and fixed that by adding the entitlement to build.settings. So I’m going to try this in my next build later this week, but if someone else gets a chance to try it first then please let us know if it clears the warning for you:
iphone = {
plist = {
--usual plist stuff here
},
entitlements = {
["com.apple.developer.game-center"] = true,
},
}