Fix invites not being disabled upon account suspension (#11412)

* Disable invite links from disabled/suspended users

* Add has_many invites relationship to users

* Destroy unused invites when suspending an account

app/models/invite.rb

@@ -17,7 +17,7 @@
 class Invite < ApplicationRecord
   include Expireable
 
-  belongs_to :user
+  belongs_to :user, inverse_of: :invites
   has_many :users, inverse_of: :invite
 
   scope :available, -> { where(expires_at: nil).or(where('expires_at >= ?', Time.now.utc)) }
@@ -25,7 +25,7 @@ class Invite < ApplicationRecord
   before_validation :set_code
 
   def valid_for_use?
-    (max_uses.nil? || uses < max_uses) && !expired?
+    (max_uses.nil? || uses < max_uses) && !expired? && !(user.nil? || user.disabled?)
   end
 
   private

app/models/user.rb

@@ -73,6 +73,7 @@ class User < ApplicationRecord
 
   has_many :applications, class_name: 'Doorkeeper::Application', as: :owner
   has_many :backups, inverse_of: :user
+  has_many :invites, inverse_of: :user
 
   has_one :invite_request, class_name: 'UserInviteRequest', inverse_of: :user, dependent: :destroy
   accepts_nested_attributes_for :invite_request, reject_if: ->(attributes) { attributes['text'].blank? }