utf8mb4 introducer added to generated column expression

[Jason Brunette]

Stock MySQL 8.0.31, Linux

CREATE TABLE `test` (
`id` int NOT NULL AUTO_INCREMENT,
`test_col` VARCHAR(45) GENERATED ALWAYS AS ("test value"),
PRIMARY KEY (`id`)
) ENGINE=InnoDB;
SELECT GENERATION_EXPRESSION FROM information_schema.columns WHERE TABLE_NAME="test" AND COLUMN_NAME="test_col";

GENERATION_EXPRESSION = _utf8mb4\'test value\'

Why does test_col's GENERATION_EXPRESSION gain the _utf8mb4 introducer? Is there something I can do to prevent this? My app has a technical need for this to not happen. Plus, this seems unnecessary with everything in MySQL 8 defaulting to utf8mb4. This began when we migrated from MySQL 5.7 to MySQL 8.0.31.

Thanks.