Remove unused partial

The last reference to this partial was removed in
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/51406, which was
merged nearly a year ago.

app/views/shared/members/_filter_2fa_dropdown.html.haml

-- filter = params[:two_factor] || 'everyone'
-- filter_options = { 'everyone' => _('Everyone'), 'enabled' => _('Enabled'), 'disabled' => _('Disabled') }
-.dropdown.inline.member-filter-2fa-dropdown{ data: { testid: 'member-filter-2fa-dropdown' } }
-  = dropdown_toggle(filter_options[filter], { toggle: 'dropdown', testid: 'dropdown-toggle' })
-  %ul.dropdown-menu.dropdown-menu-align-right.dropdown-menu-selectable
-    %li.dropdown-header
-      = _("Filter by two-factor authentication")
-    - filter_options.each do |value, title|
-      %li
-        = link_to filter_group_project_member_path(two_factor: value), class: ("is-active" if filter == value) do
-          = title

locale/gitlab.pot

@@ -14130,9 +14130,6 @@ msgstr ""
 msgid "Every year on %{day} at %{time} %{timezone}"
 msgstr ""
 
-msgid "Everyone"
-msgstr ""
-
 msgid "Everyone With Access"
 msgstr ""
 
@@ -15033,9 +15030,6 @@ msgstr ""
 msgid "Filter by test cases that are currently open."
 msgstr ""
 
-msgid "Filter by two-factor authentication"
-msgstr ""
-
 msgid "Filter by user"
 msgstr ""