CI - Update the list of MySQL containers

[macbre]

Add:

• mysql:8.1.0
• mariadb:10.6

[macbre]

MySQL 8.1.0

FAILED indexdigest/test/core/test_database.py::TestDatabase::test_get_table_columns - AssertionError: 'utf8mb3' != 'utf8'
- utf8mb3
?     ---
+ utf8
=================== 1 failed, 98 passed, 2 skipped in 4.95s ====================