DEBUG test PgSQL only with lowest

Author: mvorisek

.github/workflows/test-unit.yml

@@ -180,6 +180,7 @@ jobs:
           if [ -n "$LOG_COVERAGE" ]; then mv coverage/phpunit.cov coverage/phpunit-mariadb.cov; fi
 
       - name: "Run tests: PostgreSQL"
+        if: endsWith(matrix.type, 'Lowest')
         env:
           DB_DSN: "pgsql:host=postgres;dbname=atk4_test"
           DB_USER: atk4_test