Replaces CSS with BS4 utility class

app/assets/stylesheets/pages/pipeline_schedules.scss

-.js-pipeline-schedule-form {
-  .dropdown-select,
-  .dropdown-menu-toggle {
-    width: 100% !important;
-  }
-
+.pipeline-schedule-form {
   .gl-field-error {
     margin: 10px 0 0;
   }

app/views/projects/pipeline_schedules/_form.html.haml

-= form_for [@project.namespace.becomes(Namespace), @project, @schedule], as: :schedule, html: { id: "new-pipeline-schedule-form", class: "js-pipeline-schedule-form" } do |f|
+= form_for [@project.namespace.becomes(Namespace), @project, @schedule], as: :schedule, html: { id: "new-pipeline-schedule-form", class: "js-pipeline-schedule-form pipeline-schedule-form" } do |f|
   = form_errors(@schedule)
   .form-group.row
     .col-md-9
@@ -11,12 +11,12 @@
   .form-group.row
     .col-md-9
       = f.label :cron_timezone, _('Cron Timezone'), class: 'label-bold'
-      = dropdown_tag(_("Select a timezone"), options: { toggle_class: 'btn js-timezone-dropdown', title: _("Select a timezone"), filter: true, placeholder: s_("OfSearchInADropdown|Filter"), data: { data: timezone_data } } )
+      = dropdown_tag(_("Select a timezone"), options: { toggle_class: 'btn js-timezone-dropdown w-100', dropdown_class: 'w-100', title: _("Select a timezone"), filter: true, placeholder: s_("OfSearchInADropdown|Filter"), data: { data: timezone_data } } )
       = f.text_field :cron_timezone, value: @schedule.cron_timezone, id: 'schedule_cron_timezone', class: 'hidden', name: 'schedule[cron_timezone]', required: true
   .form-group.row
     .col-md-9
       = f.label :ref, _('Target Branch'), class: 'label-bold'
-      = dropdown_tag(_("Select target branch"), options: { toggle_class: 'btn js-target-branch-dropdown', dropdown_class: 'git-revision-dropdown', title: _("Select target branch"), filter: true, placeholder: s_("OfSearchInADropdown|Filter"), data: { data: @project.repository.branch_names, default_branch: @project.default_branch } } )
+      = dropdown_tag(_("Select target branch"), options: { toggle_class: 'btn js-target-branch-dropdown w-100', dropdown_class: 'git-revision-dropdown w-100', title: _("Select target branch"), filter: true, placeholder: s_("OfSearchInADropdown|Filter"), data: { data: @project.repository.branch_names, default_branch: @project.default_branch } } )
       = f.text_field :ref, value: @schedule.ref, id: 'schedule_ref', class: 'hidden', name: 'schedule[ref]', required: true
   .form-group.row.js-ci-variable-list-section
     .col-md-9

changelogs/unreleased/59921-pipeline-schedule.yml

+---
+title: Replaces CSS with BS4 utility class for pipeline schedules
+merge_request:
+author:
+type: other