Skip a bash test on Windows

Author: snoyberg

test/integration/tests/2433-ghc-by-version/Main.hs

@@ -1,5 +1,7 @@
 import System.Process (rawSystem)
 import Control.Exception (throwIO)
+import StackTest
+import Control.Monad (unless)
 
 main :: IO ()
-main = rawSystem "bash" ["run.sh"] >>= throwIO
+main = unless isWindows $ rawSystem "bash" ["run.sh"] >>= throwIO