remove useless code in models

app/models/avis.rb

@@ -9,7 +9,7 @@
 #  email                :string
 #  introduction         :text
 #  revoked_at           :datetime
-# tmp_expert_migrated   :boolean         default(FALSE)
+#  tmp_expert_migrated  :boolean          default(FALSE)
 #  created_at           :datetime         not null
 #  updated_at           :datetime         not null
 #  claimant_id          :integer          not null
@@ -21,9 +21,8 @@ class Avis < ApplicationRecord
   include EmailSanitizableConcern
 
   belongs_to :dossier, inverse_of: :avis, touch: true, optional: false
-  belongs_to :instructeur, optional: true
   belongs_to :experts_procedure, optional: false
-  belongs_to :claimant, class_name: 'Instructeur', optional: false
+  belongs_to :claimant, polymorphic: true, optional: false
 
   has_one_attached :piece_justificative_file
   has_one_attached :introduction_file

app/models/instructeur.rb

@@ -23,8 +23,6 @@ class Instructeur < ApplicationRecord
   has_many :previous_follows, -> { inactive }, class_name: 'Follow', inverse_of: :instructeur
   has_many :followed_dossiers, through: :follows, source: :dossier
   has_many :previously_followed_dossiers, -> { distinct }, through: :previous_follows, source: :dossier
-  has_many :avis
-  has_many :dossiers_from_avis, through: :avis, source: :dossier
   has_many :trusted_device_tokens, dependent: :destroy
 
   has_one :user, dependent: :nullify

app/services/dossier_search_service.rb

@@ -21,7 +21,7 @@ class DossierSearchService
   end
 
   def self.dossiers_by_id(id, instructeur)
-    (instructeur.dossiers.where(id: id) + instructeur.dossiers_from_avis.where(id: id)).uniq
+    instructeur.dossiers.where(id: id).uniq
   end
 
   def self.id_compatible?(number)