identite: remove the "*" for required labels

When all fields are required, it's better to say nothing.

app/views/users/dossiers/identite.html.haml

@@ -8,13 +8,9 @@
 
     %p.mb-1 Merci de remplir vos informations personnelles pour accéder à la démarche.
 
-    %span.form-label
-      %span.mandatory *
-      champs requis
-
     %fieldset
       %legend
-        = f.label :gender, class: "required"
+        = f.label :gender
       .radios
         %label
           = f.radio_button :gender, Individual::GENDER_MALE, required: true
@@ -25,14 +21,14 @@
 
     .flex
       .inline-champ
-        = f.label :prenom, class: "required"
+        = f.label :prenom
         = f.text_field :prenom, class: "small", required: true, autocomplete: 'given-name'
       .inline-champ
-        = f.label :nom, class: "required"
+        = f.label :nom
         = f.text_field :nom, class: "small", required: true, autocomplete: 'family-name'
 
     - if @dossier.procedure.ask_birthday?
-      = f.label :birthdate, class: "required"
+      = f.label :birthdate
       = f.date_field :birthdate, value: @dossier.individual.birthdate, placeholder: 'format : AAAA-MM-JJ', required: true, class: "small"
 
     = f.submit "Continuer", class: "button large primary expand"