Unable to connect to mariadb service in Gitea Actions

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I made a small reproducible repository at GitHub - Ravencentric/mariadbtest
You can see the successful workflow at Update mariadbtest.py · Ravencentric/mariadbtest@aea9d6f · GitHub
It’s pretty simple, the action sets up mariadb and the python script just connects to it. This however fails on the private gitea instance I’m working with. I cannot figure out why. The python script throws this error in Gitea Actions:

pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on 'localhost' ([Errno 111] Connection refused)")
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Please follow the example action-examples/MariaDB: Gitea actions example for MariaDB - MariaDB - Gitea: Git with a cup of tea