Remove duplicated `test_update_all_on_association_accessed_before_sav…

…e_with_explicit_foreign_key`

This was caused by #28246.

activerecord/test/cases/associations/has_many_associations_test.rb

@@ -586,20 +586,6 @@ def test_update_all_on_association_accessed_before_save
     assert_not_equal clients_proxy_id, firm.clients.object_id
   end
 
-  def test_update_all_on_association_accessed_before_save_with_explicit_foreign_key
-    # We can use the same cached proxy object because the id is available for the scope
-    firm = Firm.new(name: 'Firm', id: 100)
-    clients_proxy_id = firm.clients.object_id
-    firm.clients << Client.first
-    firm.save!
-    assert_equal firm.clients.count, firm.clients.update_all(description: 'Great!')
-    assert_equal clients_proxy_id, firm.clients.object_id
-    firm = Firm.new(name: "Firm")
-    firm.clients << Client.first
-    firm.save!
-    assert_equal firm.clients.count, firm.clients.update_all(description: "Great!")
-  end
-
   def test_update_all_on_association_accessed_before_save_with_explicit_foreign_key
     firm = Firm.new(name: "Firm", id: 100)
     firm.clients << Client.first