Remove outdated comments.

This was relevant when using arrays, but now the enum is using a numbered hash

app/models/user.rb

@@ -249,15 +249,12 @@ class User < ApplicationRecord
   enum layout: { fixed: 0, fluid: 1 }
 
   # User's Dashboard preference
-  # Note: When adding an option, it MUST go on the end of the array.
   enum dashboard: { projects: 0, stars: 1, project_activity: 2, starred_project_activity: 3, groups: 4, todos: 5, issues: 6, merge_requests: 7, operations: 8 }
 
   # User's Project preference
-  # Note: When adding an option, it MUST go on the end of the array.
   enum project_view: { readme: 0, activity: 1, files: 2 }
 
   # User's role
-  # Note: When adding an option, it MUST go on the end of the array.
   enum role: { software_developer: 0, development_team_lead: 1, devops_engineer: 2, systems_administrator: 3, security_analyst: 4, data_analyst: 5, product_manager: 6, product_designer: 7, other: 8 }, _suffix: true
 
   delegate :path, to: :namespace, allow_nil: true, prefix: true