don't clean the siret champ value

Cleaning the value is useless, when fetching the etablissement,
as the value will be re-written by the dossier update, when the user
fills in the dossier.

app/models/concerns/siret_champ_etablissement_fetchable_concern.rb

@@ -27,7 +27,7 @@ module SiretChampEtablissementFetchableConcern
 
   def clear(error: nil)
     etablissement_to_destroy = etablissement
-    update!(value: '', etablissement: nil)
+    update!(etablissement: nil)
     etablissement_to_destroy&.destroy
     error.presence
   end

spec/controllers/champs/siret_controller_spec.rb

@@ -39,10 +39,8 @@ describe Champs::SiretController, type: :controller do
       context 'when the SIRET is empty' do
         subject! { get :show, params: params, format: :turbo_stream }
 
-        it 'clears the etablissement and SIRET on the model' do
-          champ.reload
-          expect(champ.etablissement).to be_nil
-          expect(champ.value).to be_empty
+        it 'clears the etablissement on the model' do
+          expect(champ.reload.etablissement).to be_nil
         end
 
         it 'clears any information or error message' do
@@ -55,10 +53,8 @@ describe Champs::SiretController, type: :controller do
 
         subject! { get :show, params: params, format: :turbo_stream }
 
-        it 'clears the etablissement and SIRET on the model' do
-          champ.reload
-          expect(champ.etablissement).to be_nil
-          expect(champ.value).to be_empty
+        it 'clears the etablissement on the model' do
+          expect(champ.reload.etablissement).to be_nil
         end
 
         it 'displays a “SIRET is invalid” error message' do
@@ -76,10 +72,8 @@ describe Champs::SiretController, type: :controller do
 
         subject! { get :show, params: params, format: :turbo_stream }
 
-        it 'clears the etablissement and SIRET on the model' do
-          champ.reload
-          expect(champ.etablissement).to be_nil
-          expect(champ.value).to be_empty
+        it 'clears the etablissement on the model' do
+          expect(champ.reload.etablissement).to be_nil
         end
 
         it 'displays a “API is unavailable” error message' do
@@ -115,10 +109,8 @@ describe Champs::SiretController, type: :controller do
 
         subject! { get :show, params: params, format: :turbo_stream }
 
-        it 'clears the etablissement and SIRET on the model' do
-          champ.reload
-          expect(champ.etablissement).to be_nil
-          expect(champ.value).to be_empty
+        it 'clears the etablissement on the model' do
+          expect(champ.reload.etablissement).to be_nil
         end
 
         it 'displays a “SIRET not found” error message' do

spec/models/concern/siret_champ_etablissement_fetchable_concern_spec.rb

@@ -16,8 +16,6 @@ RSpec.describe SiretChampEtablissementFetchableConcern do
     subject(:fetch_etablissement!) { champ.fetch_etablissement!(siret, build_stubbed(:user)) }
 
     shared_examples 'an error occured' do |error|
-      it { expect { fetch_etablissement! }.to change { champ.reload.value }.to('') }
-
       it { expect { fetch_etablissement! }.to change { champ.reload.etablissement }.to(nil) }
 
       it { expect { fetch_etablissement! }.to change { Etablissement.count }.by(-1) }