Add deepseq to allowNewerPkgs

The `ghc-9.8` branch now includes `deepseq-1.5.0.0` (see
ghc/ghc@1228d3a4),
but many libraries' `.cabal` files only permit `deepseq < 1.5`. We add
`deepseq` to `allowNewerPkgs` in this patch so that `cabal` will ignore these
upper version bounds.

ci/MakeConstraints.hs

@@ -45,6 +45,7 @@ allowNewerPkgs = S.fromList
   , "binary"
   , "bytestring"
   , "Cabal"
+  , "deepseq"
   , "text" ] `S.union` bootPkgs
 
 constraints :: [String] -> Doc