fix migrations that were causing issues (#2581)

# What this PR does

## Which issue(s) this PR fixes

## Checklist

- [ ] Unit, integration, and e2e (if applicable) tests updated
- [ ] Documentation added (or `pr:no public docs` PR label added if not
required)
- [ ] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)

engine/apps/alerts/migrations/0022_alter_alertgroup_manual_severity.py

@@ -1,18 +1,24 @@
 # Generated by Django 3.2.20 on 2023-07-18 06:41
 
-from django.db import migrations, models
+from django.db import migrations
+import django_migration_linter as linter
 
 
 class Migration(migrations.Migration):
+    """
+    See the comment in the Migration class in engine/apps/alerts/migrations/0004_auto_20220711_1106.py,
+    we are commenting out this migration for essentially the same reason
+    """
 
     dependencies = [
         ('alerts', '0021_alter_alertgroup_started_at'),
     ]
 
     operations = [
-        migrations.AlterField(
-            model_name='alertgroup',
-            name='manual_severity',
-            field=models.IntegerField(choices=[(0, 'high'), (1, 'low'), (2, 'none')], default=2, null=True),
-        ),
+        linter.IgnoreMigration(),
+        # migrations.AlterField(
+        #     model_name='alertgroup',
+        #     name='manual_severity',
+        #     field=models.IntegerField(choices=[(0, 'high'), (1, 'low'), (2, 'none')], default=2, null=True),
+        # ),
     ]

engine/apps/alerts/migrations/0023_auto_20230718_0952.py

@@ -1,6 +1,7 @@
 # Generated by Django 3.2.20 on 2023-07-18 09:52
 
 from django.db import migrations, models
+import django_migration_linter as linter
 
 
 class Migration(migrations.Migration):
@@ -10,6 +11,7 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
+        linter.IgnoreMigration(),
         migrations.AlterModelManagers(
             name='alertgroup',
             managers=[
@@ -19,11 +21,12 @@ class Migration(migrations.Migration):
             model_name='alertgroup',
             name='alerts_aler_channel_ee84a7_idx',
         ),
-        migrations.AlterField(
-            model_name='alertgroup',
-            name='is_archived',
-            field=models.BooleanField(default=False, null=True),
-        ),
+        # see the comment in 0022_alter_alertgroup_manual_severity as to why we commented this out
+        # migrations.AlterField(
+        #     model_name='alertgroup',
+        #     name='is_archived',
+        #     field=models.BooleanField(default=False, null=True),
+        # ),
         migrations.AddIndex(
             model_name='alertgroup',
             index=models.Index(fields=['channel_id', 'resolved', 'acknowledged', 'silenced', 'root_alert_group_id'], name='alerts_aler_channel_81aeec_idx'),

engine/apps/alerts/migrations/0026_auto_20230719_1010.py

@@ -0,0 +1,27 @@
+# Generated by Django 3.2.20 on 2023-07-19 10:10
+
+from django.db import migrations
+import django_migration_linter as linter
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('alerts', '0025_auto_20230718_1042'),
+    ]
+
+    operations = [
+        linter.IgnoreMigration(),
+        migrations.RemoveField(
+            model_name='alertgroup',
+            name='is_archived',
+        ),
+        migrations.RemoveField(
+            model_name='alertgroup',
+            name='manual_severity',
+        ),
+        migrations.RemoveField(
+            model_name='alertgroup',
+            name='resolution_note_ts',
+        ),
+    ]

engine/apps/alerts/models/alert_group.py

@@ -16,7 +16,6 @@ from django.db.models.signals import post_save
 from django.dispatch import receiver
 from django.utils import timezone
 from django.utils.functional import cached_property
-from django_deprecate_fields import deprecate_field
 
 from apps.alerts.constants import AlertGroupState
 from apps.alerts.escalation_snapshot import EscalationSnapshotMixin
@@ -303,16 +302,6 @@ class AlertGroup(AlertGroupSlackRenderingMixin, EscalationSnapshotMixin, models.
     )
     reason_to_skip_escalation = models.IntegerField(choices=REASONS_TO_SKIP_ESCALATIONS, default=NO_REASON)
 
-    SEVERITY_HIGH, SEVERITY_LOW, SEVERITY_NONE = range(3)
-    SEVERITY_CHOICES = (
-        (SEVERITY_HIGH, "high"),
-        (SEVERITY_LOW, "low"),
-        (SEVERITY_NONE, "none"),
-    )
-    manual_severity = deprecate_field(models.IntegerField(choices=SEVERITY_CHOICES, default=SEVERITY_NONE))
-
-    resolution_note_ts = deprecate_field(models.CharField(max_length=100, null=True, default=None))
-
     root_alert_group = models.ForeignKey(
         "alerts.AlertGroup",
         on_delete=models.SET_NULL,
@@ -324,7 +313,6 @@ class AlertGroup(AlertGroupSlackRenderingMixin, EscalationSnapshotMixin, models.
     # NOTE: we should probably migrate this field to models.UUIDField as it's ONLY ever being
     # set to the result of uuid.uuid1
     last_unique_unacknowledge_process_id: UUID | None = models.CharField(max_length=100, null=True, default=None)
-    is_archived = deprecate_field(models.BooleanField(default=False))
 
     wiped_at = models.DateTimeField(null=True, default=None)
     wiped_by = models.ForeignKey(