The class Drupal\migrate_drupal\Plugin\migrate\source\d8\Config is deprecated. This class provides the d8_config migrate source plugin.
The new class Drupal\migrate\Plugin\migrate\source\ConfigEntity provides the config_entity migrate source plugin, which is essentially identical to the d8_config plugin.
Before Drupal 11.2.0
A migration can declare the d8_config source plugin:
source
plugin: d8_config
names:
- node.type.article
- node.type.page
The migrate_drupal module must be enabled in order to use this migration.
Drupal 11.2.0 and later
A migration can declare the config_entity source plugin:
source
plugin: config_entity
names:
- node.type.article
- node.type.page
The migrate module must be enabled in order to use this migration.
Contrib and Custom Source Plugins
The deprecated class extends Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase, which extends Drupal\migrate\Plugin\migrate\source\SqlBase. The new class extends SqlBase directly.
Any contrib or custom source plugins that currently extend Config from the migrate_drupal module should be updated to extend ConfigEntity from the migrate module. They may need further work because the properties and methods of DrupalSqlBase are no longer available.