chore(curriculum): fix + test curriculum order (#44366)

* chore(tools): test curriculum order

* chore: update orders

* fix(tests): temporarily ignore cert super

The Relational Databases cert being 'upcomingChanges' is breaking
the tests.

* fix: graphql query here

* fix: use only one meta

* chore: remove unnecessary superOrders

* chore: zero-based indexing

* fix: update mock

* refactor: remove unused fixture

Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>

curriculum/challenges/_meta/css-flexbox/meta.json

@@ -7,7 +7,7 @@
   "template": "",
   "required": [],
   "superBlock": "responsive-web-design",
-  "superOrder": 1,
+  "superOrder": 0,
   "challengeOrder": [
     [
       "587d78ab367417b2b2512af0",