Fix fixture_path deprecation warning

This is now plural

```
Rails 7.1 has deprecated the singular fixture_path in favour of an array.You should migrate to plural:
```

spec/rails_helper.rb

@@ -34,7 +34,7 @@
 end
 RSpec.configure do |config|
   # Remove this line if you're not using ActiveRecord or ActiveRecord fixtures
-  config.fixture_path = "#{::Rails.root}/spec/fixtures"
+  config.fixture_paths = ["#{::Rails.root}/spec/fixtures"]
 
   # If you're not using ActiveRecord, or you'd prefer not to run each of your
   # examples within a transaction, remove the following line or assign false