ci: use mariadb 10.6 (#33220)

https://github.com/frappe/frappe/pull/19116

[skip ci]
diff --git a/.github/helper/site_config_mariadb.json b/.github/helper/site_config_mariadb.json
index 948ad08..49e7fcf 100644
--- a/.github/helper/site_config_mariadb.json
+++ b/.github/helper/site_config_mariadb.json
@@ -9,7 +9,7 @@
  "mail_password": "test",
  "admin_password": "admin",
  "root_login": "root",
- "root_password": "travis",
+ "root_password": "root",
  "host_name": "http://test_site:8000",
  "install_apps": ["erpnext"],
  "throttle_user_limit": 100