[update] date_cotisation not required in database

models/scop_cotisation.py

@@ -43,7 +43,10 @@ class ScopCotisation(models.AbstractModel):
         domain=[('is_contribution', '=', True)],
         required=True,
     )
-    date_cotisation = fields.Date("Date de cotisation", required=True)
+    date_cotisation = fields.Date(
+        string="Date calcul cotisation",
+        help="Date de calcul qui apparaitra sur le bordereau de cotisation"
+    )
 
     member_count = fields.Integer(
         "Adhérents renouvelés",