ci: change oc main version to 17.1

Author: bluetom

.github/workflows/config.json

@@ -1,7 +1,7 @@
 {
   "main-moodle": "MOODLE_500_STABLE",
   "main-php": "8.3",
-  "main-oc": "16.7",
+  "main-oc": "17.1",
   "ocs": ["17.1", "16.7", "15.11"],
   "main-db": "mariadb",
   "moodle-php": {