Replace `ListT`

[andreasabel]

We got to get rid of ListT if we want to compile with transformers-0.6 (enabled by mtl-2.3).

src/Distribution/Server/Features/Search/ExtractNameTerms.hs:60:41: warning: [-Wdeprecations]
    In the use of type constructor or class ‘ListT’
    (imported from Control.Monad.List, but defined in Control.Monad.Trans.List):
    Deprecated: "This transformer is invalid on most monads"
   |
60 | newtype Split a = Split (StateT String (ListT (WriterT [String] Identity)) a)
   |                                         ^^^^^

src/Distribution/Server/Features/Search/ExtractNameTerms.hs:70:43: warning: [-Wdeprecations]
    In the use of ‘runListT’
    (imported from Control.Monad.List, but defined in Control.Monad.Trans.List):
    Deprecated: "This transformer is invalid on most monads"
   |
70 | runSplitter (Split m) s = snd (runWriter (runListT (runStateT m s)))