Use GitLab UI buttons in Slack Application Service

Add Changelog

Update 231173-gl-button.yml

changelogs/unreleased/231173-gl-button.yml

+---
+title: Apply GitLab UI button styles to buttons in gitlab_slack_application file
+merge_request: 53478
+author: Yogi (@yo)
+type: other

ee/app/views/projects/services/gitlab_slack_application/_slack_integration_form.html.haml

@@ -23,8 +23,8 @@
       %td
         .controls
           - project = @service.project
-          = link_to 'Edit', edit_project_settings_slack_path(project), class: 'btn btn-sm'
-          = link_to 'Remove', project_settings_slack_path(project), method: :delete, class: 'btn btn-danger btn-sm', data: { confirm: 'Are you sure?' }
+          = link_to 'Edit', edit_project_settings_slack_path(project), class: 'btn gl-button btn-default btn-sm'
+          = link_to 'Remove', project_settings_slack_path(project), method: :delete, class: 'btn gl-button btn-danger btn-sm', data: { confirm: 'Are you sure?' }
 - else
   %p To set up this service press "Add to Slack"
   = render "projects/services/#{@service.to_param}/slack_button", project: @project