Deprecation: #86323 - Configuration key “site” in YAML site configuration

See Issue #86323

Description

The site configuration is a file called config in a folder called sites and does not need a site key to identify its purpose. To keep writing the config as easy as possible, the site configuration moved one level up and now resides directly in config.yaml.

Impact

Having the site configuration below the key “site” has been marked as deprecated and will trigger a PHP E_USER_DEPRECATED error.

Affected Installations

Installations with a site config that have a key “site” are affected.

Migration

Remove the “site” key and first level indentation either by directly editing the YAML file or by saving via the sites module.