grade-school: replace zip (repeat g) with map (g,)

https://github.com/ndmitchell/hlint/blob/master/CHANGES.txt
3.5, released 2022-09-20
    [#1421][1421], change zip/repeat to map with tuple section

[1421]: ndmitchell/hlint#1421

Author: petertseng

exercises/practice/grade-school/test/Tests.hs

@@ -1,4 +1,5 @@
 {-# OPTIONS_GHC -fno-warn-type-defaults #-}
+{-# LANGUAGE TupleSections #-}
 
 import Test.Hspec        (Spec, it, shouldBe)
 import Test.Hspec.Runner (configFastFail, defaultConfig, hspecWith)
@@ -12,7 +13,7 @@ specs :: Spec
 specs = do
 
           let fromList = foldr (uncurry add) empty
-          let fromGrade g = fromList . zip (repeat g)
+          let fromGrade g = fromList . map (g,)
 
           it "add student" $
             sorted (add 2 "Aimee" empty) `shouldBe` [(2, ["Aimee"])]