Fix 8.6.5 build

Author: pepeiborra

ghcide/bench/lib/Experiments.hs

@@ -25,6 +25,7 @@ module Experiments
 import           Control.Applicative.Combinators (skipManyTill)
 import           Control.Exception.Safe          (IOException, handleAny, try)
 import           Control.Monad.Extra
+import           Control.Monad.Fail
 import           Control.Monad.IO.Class
 import           Data.Aeson                      (Value (Null), toJSON)
 import           Data.Either                     (fromRight)