Replace Mocha#stubs with assert_called_with

A correct, but not obvious use of `ActiveSupport::Testing::MethodCallAssertions`, which might also have been part of rails#33337 or rails#33391.

activerecord/test/cases/adapters/mysql2/active_schema_test.rb

@@ -157,14 +157,19 @@ def test_remove_timestamps
   end
 
   def test_indexes_in_create
-    ActiveRecord::Base.connection.stubs(:data_source_exists?).with(:temp).returns(false)
+    assert_called_with(
+      ActiveRecord::Base.connection,
+      :data_source_exists?,
+      [:temp],
+      returns: false
+    ) do
+      expected = "CREATE TEMPORARY TABLE `temp` ( INDEX `index_temp_on_zip`  (`zip`)) AS SELECT id, name, zip FROM a_really_complicated_query"
+      actual = ActiveRecord::Base.connection.create_table(:temp, temporary: true, as: "SELECT id, name, zip FROM a_really_complicated_query") do |t|
+        t.index :zip
+      end
 
-    expected = "CREATE TEMPORARY TABLE `temp` ( INDEX `index_temp_on_zip`  (`zip`)) AS SELECT id, name, zip FROM a_really_complicated_query"
-    actual = ActiveRecord::Base.connection.create_table(:temp, temporary: true, as: "SELECT id, name, zip FROM a_really_complicated_query") do |t|
-      t.index :zip
+      assert_equal expected, actual
     end
-
-    assert_equal expected, actual
   end
 
   private