ActionView::Template::Error: undefined method `any?' for nil:NilClass

https://sentry.gitlap.com/gitlab/gitlabcom/issues/23771/

ActiveRecord::StaleObjectError: Attempted to update a stale object: MergeRequest
  config/initializers/ar_monkey_patch.rb:44:in `_update_record'
    raise ActiveRecord::StaleObjectError.new(self, "update")
  app/services/issuable_base_service.rb:219:in `block in update'
    if issuable.with_transaction_returning_status { issuable.save }
  app/services/issuable_base_service.rb:219:in `update'
    if issuable.with_transaction_returning_status { issuable.save }
  lib/gitlab/metrics/instrumentation.rb:156:in `block in update'
    trans.method_call_for(#{label.to_sym.inspect}).measure { super }
  lib/gitlab/metrics/method_call.rb:23:in `measure'
    retval = yield
...
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NoMethodError: undefined method `any?' for nil:NilClass
  app/views/shared/issuable/_approvals.html.haml:68:in `_app_views_shared_issuable__approvals_html_haml__1069122021643708322_70274121153900'
    - if @suggested_approvers.any?
  app/views/shared/issuable/_form.html.haml:44:in `_app_views_shared_issuable__form_html_haml__2231377154898265212_70274147452300'
    = render 'shared/issuable/approvals', issuable: issuable, form: form
  app/views/projects/merge_requests/_form.html.haml:2:in `block in _app_views_projects_merge_requests__form_html_haml__3201598675469662771_70274188326920'
    = render 'shared/issuable/form', f: f, issuable: @merge_request
  app/views/projects/merge_requests/_form.html.haml:1:in `_app_views_projects_merge_requests__form_html_haml__3201598675469662771_70274188326920'
    = form_for [@project.namespace.becomes(Namespace), @project, @merge_request], html: { class: 'merge-request-form form-horizontal common-note-form js-requires-input js-quick-submit' } do |f|
  app/views/projects/merge_requests/edit.html.haml:6:in `_app_views_projects_merge_requests_edit_html_haml___4262369435492867599_70274193445700'
    = render 'form'
...
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ActionView::Template::Error: undefined method `any?' for nil:NilClass

ActionView::Template::Error: undefined method `any?' for nil:NilClass