Error running BrowserTest (Drupal\Core\Config\Schema\SchemaIncompleteException: No schema ...)
The Schema file is: https://github.com/aneek/rate_limiter/blob/develop/config/install/rate_limiter.settings.yml


No, that is not the schema file, that is the config file for which you need to create a configuration schema.

Tests by default enforce that your configuration has a schema, which is useful for supporting configuration translation and additional upcoming functionality like validation.

See Configuration schema/metadata for more information on how to create that.