Revert "Use default value when DB_NAME constant is not defined"

This reverts commit f8894c7.

Author: JanJakes

constants.php

@@ -52,16 +52,6 @@
 	}
 }
 
-/**
- * The DB_NAME constant is required by the SQLite driver.
- *
- * When DB_NAME is not defined, let's use a default value that corresponds to
- * the default value of the constant in "wp-config-sample.php" and in Studio.
- */
-if ( ! defined( 'DB_NAME' ) ) {
-	define( 'DB_NAME', 'database_name_here' );
-}
-
 // Allow enabling the SQLite AST driver via environment variable.
 if ( ! defined( 'WP_SQLITE_AST_DRIVER' ) && isset( $_ENV['WP_SQLITE_AST_DRIVER'] ) && 'true' === $_ENV['WP_SQLITE_AST_DRIVER'] ) {
 	define( 'WP_SQLITE_AST_DRIVER', true );