fix[parse]: Clones the result vector only once.

I removed a `force`, I noticed that `freeze` was already doing a clone.

src/Language/Brainfuck.hs

@@ -3,7 +3,6 @@
 {-# LANGUAGE LambdaCase #-}
 module Language.Brainfuck (parse, ParseFailure, render) where
 
-import Control.Monad ((<$!>))
 import Control.Monad.ST (runST, ST)
 
 import Data.Text ( Text )
@@ -48,7 +47,7 @@ parse text = runST $ do
     parseBlock :: Text -> MVector s Instruction -> Int -> ST s (Either ParseFailure (Vector Instruction, Text))
     parseBlock Text.Empty instructions index = do
       let populatedSlice = MutableVector.take index instructions
-      frozen <- Vector.force <$!> Vector.freeze populatedSlice
+      frozen <- Vector.freeze populatedSlice
       pure . Right $ (frozen, Text.empty)
     parseBlock t@(c Text.:< cs) instructions index = let
 
@@ -65,7 +64,7 @@ parse text = runST $ do
                 '.' -> recognizeInstruction PutByte   cs
                 ']' -> do
                   let populatedSlice = MutableVector.take index instructions
-                  frozen <- Vector.force <$!> Vector.freeze populatedSlice
+                  frozen <- Vector.freeze populatedSlice
                   pure $ Right (frozen, t)
                 '[' -> do
                   innerVector <- MutableVector.new (Text.length cs)