I wanted to tell you that mariaDB and MySQL are same and there ain't no difference in DML of both databases.
I am afraid that your database version is older as support for json columns came late in 2016/7.
So please update the version of your database:
Please check out the system requirements also before installing Bagisto on https://github.com/bagisto/bagsito
This is due to improper seeding of data in database so kindly drop table of database, once again run 'php artisan migrate' then 'php artisan db:seed' & make sure that all of this process executes without error.
The issue is regarding the MariaDB version that you are using with your XAMPP. Kindly update your MariaDB version from 10.1 TO 10.2. You can refer to this stack here: https://stackoverflow.com/questions/44027926/update-xampp-from-maria-db-10-1-to-10-2