Remove CeleryTask model and mutex (saleor#12695)

* Remove CeleryTask model and mutex

* Clarify comment about not seperating state and db in migration

saleor/core/migrations/0007_delete_celerytask.py

@@ -0,0 +1,17 @@
+# Generated by Django 3.2.18 on 2023-04-27 07:56
+
+from django.db import migrations
+
+
+# No need to seperate state and db, cause CeleryTask model
+# is no longer used in code in SaleorCore.
+class Migration(migrations.Migration):
+    dependencies = [
+        ("core", "0006_celerytask"),
+    ]
+
+    operations = [
+        migrations.DeleteModel(
+            name="CeleryTask",
+        ),
+    ]

saleor/core/models.py

@@ -183,7 +183,3 @@ class EventDeliveryAttempt(models.Model):
 
     class Meta:
         ordering = ("-created_at",)
-
-
-class CeleryTask(Job):
-    name = models.CharField(max_length=255, unique=True)

saleor/core/tasks.py

@@ -1,36 +1,11 @@
-from contextlib import contextmanager
-
 from botocore.exceptions import ClientError
 from django.conf import settings
 from django.core.files.storage import default_storage
 from django.db.models import Exists, OuterRef, Q
 from django.utils import timezone
 
 from ..celeryconf import app
-from .models import CeleryTask, EventDelivery, EventDeliveryAttempt, EventPayload
-
-
-@contextmanager
-def celery_task_lock(task_name: str):
-    """Celery task lock.
-
-    This contextmanager provides lock on database for executing celery task.
-
-    Parameters
-    ----------
-    task_name : str
-        Unique name of the celery task.
-
-    """
-
-    lock = None
-    created = False
-    try:
-        lock, created = CeleryTask.objects.get_or_create(name=task_name)
-        yield lock, created
-    finally:
-        if lock and created:
-            lock.delete()
+from .models import EventDelivery, EventDeliveryAttempt, EventPayload
 
 
 @app.task