Try to change host of MySQL service

Author: ZhukV

.github/workflows/tests.yaml

@@ -71,7 +71,7 @@ jobs:
                     - 3306:3306
 
         env:
-            MYSQL_DSN: mysql:host=127.0.0.1;dbname=migrations
+            MYSQL_DSN: mysql:host=mysql;dbname=migrations
             MYSQL_USER: migrator
             MYSQL_PASSWORD: 'Q1w2e3r4'