Remove reference to details.js

As of govuk-frontend v5, the details component does not use JS and the .js file has been removed from the package.

Remove the `data-module="govuk-details"` attribute

See 'Remove references to the JavaScript for the Details component' from https://github.com/alphagov/govuk-frontend/releases/tag/v5.0.0

app/assets/javascripts/govuk_publishing_components/components/details.js

@@ -1,7 +1,5 @@
-// = require govuk/components/details/details.bundle.js
 window.GOVUK = window.GOVUK || {}
 window.GOVUK.Modules = window.GOVUK.Modules || {}
-window.GOVUK.Modules.GovukDetails = window.GOVUKFrontend.Details;
 
 (function (Modules) {
   function GemDetails ($module) {

app/views/govuk_publishing_components/components/_details.html.erb

@@ -13,8 +13,8 @@
   css_classes << shared_helper.get_margin_bottom
 
   details_data_attributes = {}
-  details_data_attributes[:module] = 'govuk-details gem-details'
-  details_data_attributes[:module] = 'govuk-details gem-details ga4-event-tracker' unless disable_ga4
+  details_data_attributes[:module] = 'gem-details'
+  details_data_attributes[:module] = 'gem-details ga4-event-tracker' unless disable_ga4
 
   data_attributes ||= {}
   data_attributes[:details_track_click] = ''

spec/components/details_spec.rb

@@ -10,7 +10,7 @@ def component_name
       "This is more info"
     end
 
-    assert_select "details.gem-c-details[data-module='govuk-details gem-details ga4-event-tracker']"
+    assert_select "details.gem-c-details[data-module='gem-details ga4-event-tracker']"
     assert_select ".govuk-details__summary-text[data-ga4-expandable]", text: "Some title"
     assert_select ".govuk-details__text", text: "This is more info"
   end