Support MariaDB default values for timestamp

[critrun]

What do you want to change?

If I create a table like for example:

CREATE TABLE IF NOT EXISTS `session` (
    `id` INT NOT NULL,
    `expiry` TIMESTAMP NOT NULL DEFAULT (CURRENT_TIMESTAMP + INTERVAL 30 DAY),
    PRIMARY KEY (`id`)
);

Currently this default for the expiry will not work as it causes syntax error, as this isn't a feature for mysql but only mariadb from my understanding. It would be nice to have these more programmatic defaults work with sqlc.

What database engines need to be changed?

MySQL

What programming language backends need to be changed?

No response