Do import at correct part of unittests

Author: MilesCranmer

test/unittest.jl

@@ -4,14 +4,14 @@ VERSION >= v"1.9" && @safetestset "Test Aqua.jl" begin
     include("test_aqua.jl")
 end
 
-@safetestset "Test Optim.jl" begin
-    include("test_optim.jl")
-end
-
 @safetestset "Initial error handling test" begin
     include("test_initial_errors.jl")
 end
 
+@safetestset "Test Optim.jl" begin
+    include("test_optim.jl")
+end
+
 @safetestset "Test tree construction and scoring" begin
     include("test_tree_construction.jl")
 end