Prevent breaking change for assertion message in test

Follow up rubocop/rubocop#11729.

This PR prevents breaking change for assertion message in test. e.g.

```console
% bundle exec ruby -Itest test/rubocop/cop/minitest/lifecycle_hooks_order_test.rb
(snip)

Fabulous run in 0.075080s, 93.2339 runs/s, 93.2339 assertions/s.

  1) Failure:
LifecycleHooksOrderTest#test_registers_offense_when_hooks_are_not_before_test_cases [test/rubocop/cop/minitest/lifecycle_hooks_order_test.rb:62]:
--- expected
+++ actual
@@ -4,7 +4,7 @@
   end

   def setup; end
-  ^^^^^^^^^^^^^^ `setup` is supposed to appear before `test_something`.
+  ^^^^^^^^^^^^^^ Minitest/LifecycleHooksOrder: `setup` is supposed to appear before `test_something`.
   def teardown; end
 end
 "
```

changelog/fix_prevent_breaking_change_for_assertion_message_in_test.md

@@ -0,0 +1 @@
+* [#247](https://github.com/rubocop/rubocop-minitest/pull/247): Prevent breaking change for assertion message in test. ([@koic][])

lib/rubocop/minitest/assert_offense.rb

@@ -79,7 +79,7 @@ def setup
         cop_name = self.class.to_s.delete_suffix('Test')
         return unless RuboCop::Cop::Minitest.const_defined?(cop_name)
 
-        @cop = RuboCop::Cop::Minitest.const_get(cop_name).new
+        @cop = RuboCop::Cop::Minitest.const_get(cop_name).new(configuration)
       end
 
       def format_offense(source, **replacements)