Handle button_helpers keyword parameter deprecation
Handle button_helpers keyword parameter deprecation

Fix the deprecation, that will break in ruby 3.0
```
lib/govuk_component/button_helpers_spec.rb: warning: Using the last argument as keyword parameters is deprecated; maybe ** should be added to the call
```
Effects numerous lines

ministryofjustice/advocate-defence-payments,ministryofjustice/advocate-defence-payments,ministryofjustice/advocate-defence-payments,ministryofjustice/advocate-defence-payments