Disable -Wredundant-constraints in a module that uses custom type errors

Also, constraint extensible-effects to < 2 in benchmarks to use the
non-freer implementation.

package.yaml

@@ -83,7 +83,7 @@ benchmarks:
     ghc-options: -O2
     dependencies:
     - criterion
-    - extensible-effects
+    - extensible-effects < 2
     - free
     - freer-simple
     - mtl

src/Data/OpenUnion/Internal.hs

@@ -1,3 +1,4 @@
+{-# OPTIONS_GHC -Wno-redundant-constraints #-} -- Due to use of TypeError.
 {-# OPTIONS_HADDOCK not-home #-}
 
 {-# LANGUAGE AllowAmbiguousTypes #-}

stack.yaml

@@ -3,7 +3,8 @@ resolver: lts-8.21
 packages:
 - '.'
 
-extra-deps: []
+extra-deps:
+- extensible-effects-1.11.1.0
 
 flags: {}
 extra-package-dbs: []