fix(sla): reset in-memory async_updating after dispatch

Before the pickle removal, the SLA recompute task received the
SLA_Configuration / Product instances by reference (Celery's sync
.apply() does not serialize). The inner update function set
async_updating=False on those shared instances, so the dispatcher's
local self.async_updating ended up False as well.

After switching the dispatch to pass IDs and refetch in the task, the
inner function only resets async_updating on its refetched copies.
The dispatcher's in-memory self.async_updating stayed True, so a
subsequent save() on the same instance triggered the lock-revert path
at SLA_Configuration.save() line 1058 and overwrote the caller's
field changes (e.g. enforce_critical) with the DB values.

Manifested as test_sla_expiration_date_after_sla_not_enforced failing:
sla_config.enforce_critical=False was reverted to True on save.

Reset async_updating on the in-memory caller instances after
dispatch returns to keep them consistent with the post-task DB state.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Maffooch

dojo/models.py

@@ -1099,6 +1099,10 @@ def save(self, *args, **kwargs):
                     list(products.values_list("id", flat=True)),
                     severities=severities,
                 )
+                # The async task refetches and resets async_updating on its own copy.
+                # Mirror that on this in-memory instance so a subsequent save() on the
+                # same instance does not trigger the lock-revert path at line 1058.
+                self.async_updating = False
 
     def clean(self):
         sla_days = [self.critical, self.high, self.medium, self.low]
@@ -1265,6 +1269,12 @@ def save(self, *args, **kwargs):
                     sla_config.id,
                     [self.id],
                 )
+                # The async task refetches and resets async_updating on its own copies.
+                # Mirror that on this in-memory product and the in-memory sla_config so a
+                # subsequent save() on either does not trigger their lock-revert paths.
+                self.async_updating = False
+                if sla_config:
+                    sla_config.async_updating = False
 
     def get_absolute_url(self):
         return reverse("view_product", args=[str(self.id)])