only use Aqua on >= 1.9

Author: chriselrod

test/grouptests.jl

@@ -13,9 +13,10 @@ const START_TIME = time()
   end
 
   @time if LOOPVECTORIZATION_TEST == "all" || LOOPVECTORIZATION_TEST == "part2"
+    if VERSION >= v"1.9"
       using Aqua
       @time Aqua.test_all(LoopVectorization, ambiguities = false, piracy = false)
-
+    end
     @test isempty(detect_unbound_args(LoopVectorization))
 
     @time include("printmethods.jl")