ghc-experimental: Add dummy dependencies to work around #23942

This is a temporary measure to improve CI reliability until a proper
solution is developed.

Works around #23942.

libraries/ghc-experimental/src/Data/Sum/Experimental.hs

@@ -80,4 +80,5 @@ module Data.Sum.Experimental (
   Sum63#,
 ) where
 
+import GHC.Num.BigNat () -- for build ordering
 import GHC.Types

libraries/ghc-experimental/src/Data/Tuple/Experimental.hs

@@ -161,3 +161,4 @@ module Data.Tuple.Experimental (
 import GHC.Tuple
 import GHC.Types
 import GHC.Classes
+import GHC.Num.BigNat () -- for build ordering