Fix missed connection handler call

In #45924 I updated the methods on connection handler to clear all
connections regardless of role. I missed this call because it doesn't
throw deprecation warnings in the Active Record tests.

activerecord/lib/active_record/migration.rb

@@ -646,7 +646,7 @@ def load_schema_if_pending!
           # Roundtrip to Rake to allow plugins to hook into database initialization.
           root = defined?(ENGINE_ROOT) ? ENGINE_ROOT : Rails.root
           FileUtils.cd(root) do
-            Base.connection_handler.clear_all_connections!
+            Base.connection_handler.clear_all_connections!(:all)
             system("bin/rails db:test:prepare")
           end
         end