Fix minor typos in comments and spec names (#21831)

spec/controllers/admin/confirmations_controller_spec.rb

@@ -32,7 +32,7 @@ RSpec.describe Admin::ConfirmationsController do
     end
   end
 
-  describe 'POST #resernd' do
+  describe 'POST #resend' do
     subject { post :resend, params: { account_id: user.account.id } }
 
     let!(:user) { Fabricate(:user, confirmed_at: confirmed_at) }