serialize can_be_deleted field only when needed

app/controllers/admin/users_controller.rb

@@ -32,7 +32,7 @@ class Admin::UsersController < Admin::StaffController
   def index
     users = ::AdminUserIndexQuery.new(params).find_users
 
-    opts = {}
+    opts = { include_can_be_deleted: true }
     if params[:show_emails] == "true"
       StaffActionLogger.new(current_user).log_show_emails(users, context: request.path)
       opts[:emails_desired] = true

app/serializers/admin_user_list_serializer.rb

@@ -116,4 +116,8 @@ class AdminUserListSerializer < BasicUserSerializer
   def can_be_deleted
     scope.can_delete_user?(object)
   end
+
+  def include_can_be_deleted?
+    @options[:include_can_be_deleted]
+  end
 end

spec/serializers/admin_user_list_serializer_spec.rb

@@ -89,4 +89,24 @@ RSpec.describe AdminUserListSerializer do
       expect(json[:secondary_emails]).to contain_exactly("first@email.com", "second@email.com")
     end
   end
+
+  describe "#can_be_deleted" do
+    it "is not included if the include_can_be_deleted option is not present" do
+      json = AdminUserListSerializer.new(user, scope: guardian, root: false).as_json
+
+      expect(json.key?(:can_be_deleted)).to eq(false)
+    end
+
+    it "is included if the include_can_be_deleted option is true" do
+      json =
+        AdminUserListSerializer.new(
+          user,
+          scope: guardian,
+          root: false,
+          include_can_be_deleted: true,
+        ).as_json
+
+      expect(json[:can_be_deleted]).to eq(true)
+    end
+  end
 end