Don't test Enzyme on 1.12

Author: kshyatt

test/runtests.jl

@@ -38,8 +38,10 @@ if !is_buildkite
     @safetestset "Image and Null Space" begin
         include("orthnull.jl")
     end
-    @safetestset "Enzyme" begin
-        include("enzyme.jl")
+    if VERSION < v"1.12.0" # revisit when Enzyme is more stable on 1.12
+        @safetestset "Enzyme" begin
+            include("enzyme.jl")
+        end
     end
     @safetestset "Mooncake" begin
         include("mooncake.jl")