Remove the updateLibsassVersion from Setup.hs

It should not be required now - libsass generates the version on the fly
using `git` and passes it as environment variable.

Setup.hs

@@ -38,7 +38,6 @@ main = defaultMainWithHooks hooksFix
           , preBuild = updateLibDirs
           , postCopy = copyLibsass
           , postClean = cleanLibsass
-          , preSDist = updateLibsassVersion
         }
         -- Fix for Cabal-1.18 - it does not `copy` on `install`, so we `copy` on
         -- `install` manually. ;)
@@ -140,14 +139,6 @@ cleanLibsass :: Args -> CleanFlags -> PackageDescription -> () -> IO ()
 cleanLibsass _ flags _ _ =
     execMake (fromFlag $ cleanVerbosity flags) "" "clean"
 
-updateLibsassVersion :: Args -> SDistFlags -> IO HookedBuildInfo
-updateLibsassVersion _ flags = do
-    let verbosity = fromFlag $ sDistVerbosity flags
-    ver <- rawSystemStdout verbosity "env" [ "git", "-C", "libsass", "describe",
-        "--abbrev=4", "--dirty", "--always", "--tags" ]
-    writeFile "libsass/VERSION" ver
-    return emptyHookedBuildInfo
-
 #if MIN_VERSION_Cabal(2, 2, 0)
 getCabalFlag :: String -> ConfigFlags -> Bool
 getCabalFlag name flags = fromMaybe False (lookupFlagAssignment (mkFlagName name') allFlags)