skip useless checks when creating a subscription for a new member

subscription/forms.py

@@ -94,6 +94,13 @@ class SubscriptionNewUserForm(SubscriptionForm):
         return email
 
     def clean(self) -> dict[str, Any]:
+        """Initialize the [User][core.models.User] linked to this subscription.
+
+        Warning:
+            The `User` is initialized, but not saved.
+            Don't use it for operations that expect
+            a persisted object.
+        """
         member = User(
             first_name=self.cleaned_data.get("first_name"),
             last_name=self.cleaned_data.get("last_name"),

subscription/models.py

@@ -92,9 +92,13 @@ class Subscription(models.Model):
         self.member.make_home()
 
     def get_absolute_url(self):
-        return reverse("core:user_edit", kwargs={"user_id": self.member.pk})
+        return reverse("core:user_edit", kwargs={"user_id": self.member_id})
 
     def clean(self):
+        if self.member._state.adding:
+            # if the user is being created, then it makes no sense
+            # to check if the user is already subscribed
+            return
         today = localdate()
         threshold = timedelta(weeks=settings.SITH_SUBSCRIPTION_END)
         # a user may subscribe if :