Tests: use code interface for Member create/update (actor propagation)

test/membership/custom_field_deletion_test.exs

@@ -239,13 +239,14 @@ defmodule Mv.Membership.CustomFieldDeletionTest do
 
   # Helper functions
   defp create_member(actor) do
-    Member
-    |> Ash.Changeset.for_create(:create_member, %{
-      first_name: "Test",
-      last_name: "User#{System.unique_integer([:positive])}",
-      email: "test#{System.unique_integer([:positive])}@example.com"
-    })
-    |> Ash.create(actor: actor)
+    Mv.Membership.create_member(
+      %{
+        first_name: "Test",
+        last_name: "User#{System.unique_integer([:positive])}",
+        email: "test#{System.unique_integer([:positive])}@example.com"
+      },
+      actor: actor
+    )
   end
 
   defp create_custom_field(name, value_type, actor) do