chore(tools): test for instructions in schema (freeCodeCamp#60323)

Co-authored-by: Huyen Nguyen <25715018+huyenltnguyen@users.noreply.github.com>

Author: a2937

curriculum/schema/challenge-schema.js

@@ -209,7 +209,11 @@ const schema = Joi.object()
     }),
     forumTopicId: Joi.number(),
     id: Joi.objectId().required(),
-    instructions: Joi.string().allow(''),
+    instructions: Joi.string().when('challengeType', {
+      is: [challengeTypes.pythonProject, challengeTypes.codeAllyCert],
+      then: Joi.string().min(1).required(),
+      otherwise: Joi.string().allow('')
+    }),
     isComingSoon: Joi.bool(),
     isLocked: Joi.bool(),
     isPrivate: Joi.bool(),