Fix disabled style for mirror settings field

- We shouldn't use gl-form-input for `<select>`
- See https://gitlab.com/gitlab-org/gitlab/-/issues/338792#note_812741524

Changelog: fixed

app/views/projects/mirrors/_authentication_method.html.haml

@@ -6,7 +6,7 @@
   .select-wrapper
     = f.select :auth_method,
         options_for_select(auth_options, mirror.auth_method),
-        {}, { class: "form-control gl-form-input select-control js-mirror-auth-type qa-authentication-method" }
+        {}, { class: "form-control gl-form-select select-control js-mirror-auth-type qa-authentication-method" }
     = sprite_icon('chevron-down', css_class: "gl-icon gl-absolute gl-top-3 gl-right-3 gl-text-gray-200")
     = f.hidden_field :auth_method, value: "password", class: "js-hidden-mirror-auth-type"
 

app/views/projects/mirrors/_mirror_repos_form.html.haml

 .form-group
   = label_tag :mirror_direction, _('Mirror direction'), class: 'label-light'
   .select-wrapper
-    = select_tag :mirror_direction, options_for_select([[_('Push'), 'push']]), class: 'form-control gl-form-input select-control js-mirror-direction qa-mirror-direction', disabled: true
+    = select_tag :mirror_direction, options_for_select([[_('Push'), 'push']]), class: 'form-control gl-form-select select-control js-mirror-direction qa-mirror-direction', disabled: true
     = sprite_icon('chevron-down', css_class: "gl-icon gl-absolute gl-top-3 gl-right-3 gl-text-gray-200")
 
 = render partial: "projects/mirrors/mirror_repos_push", locals: { f: f }

ee/app/views/projects/mirrors/_mirror_repos_form.html.haml

@@ -10,7 +10,7 @@
 .form-group
   = label_tag :mirror_direction, _('Mirror direction'), class: 'label-light'
   .select-wrapper
-    = select_tag :mirror_direction, options_for_select(direction_options), class: 'form-control gl-form-input select-control js-mirror-direction qa-mirror-direction', disabled: (direction_options.count == 1) || has_existing_pull_mirror
+    = select_tag :mirror_direction, options_for_select(direction_options), class: 'form-control gl-form-select select-control js-mirror-direction qa-mirror-direction', disabled: (direction_options.count == 1) || has_existing_pull_mirror
     = sprite_icon('chevron-down', css_class: "gl-icon gl-absolute gl-top-3 gl-right-3 gl-text-gray-200")
 
 .js-form-insertion-point