Update aqua.jl

test/aqua.jl

@@ -6,6 +6,16 @@ import Aqua
 @testset "Aqua" begin
     # Test ambiguities separately without Base and Core
     # Ref: https://github.com/JuliaTesting/Aqua.jl/issues/77
-    Aqua.test_all(Distributions; ambiguities = false)
-    Aqua.test_ambiguities(Distributions)
+    Aqua.test_all(
+        Distributions;
+        ambiguities = false,
+        # On older Julia versions, installed dependencies are quite old
+        # Thus unbound type parameters show up that are fixed in newer versions
+        unbound_args = VERSION >= v"1.6",
+    )
+    # Tests are not reliable on older Julia versions and
+    # show ambiguities in loaded packages
+    if VERSION >= v"1.6"
+        Aqua.test_ambiguities(Distributions)
+    end
 end