fix: port mapping for mariadb service

Author: d4rpx1

.github/workflows/gradle.yml

@@ -45,7 +45,7 @@ jobs:
       mariadb:
         image: mariadb:latest
         ports:
-          - 3306
+          - 3306:3306
         env:
           MYSQL_DATABASE: matrix
           MYSQL_ROOT_PASSWORD: root