🗃️(backend) fix storage_location for existing files stored on AWS

The `storage_location` field was introduced in a previous release with a
default value of `SCW_S3` for new files.
However, existing files are stored on AWS S3.
This commit updates the migration to correctly set `storage_location` to
`AWS_S3` for those existing records.

Author: wilbrdt

CHANGELOG.md

@@ -8,6 +8,13 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Fixed
+
+- Fix storage location field for existing files stored on AWS S3:
+  - markdown images
+  - deposited files
+  - clasroom documents
+
 ## [5.8.0] - 2025-06-06
 
 ### Added

src/backend/marsha/bbb/migrations/0025_classroomdocument_fill_storage_location.py

@@ -0,0 +1,19 @@
+# Generated by Django 5.0.9 on 2025-06-11 17:34
+
+from django.db import migrations
+
+
+def set_storage_location_to_aws(apps, schema_editor):
+    """Update the storage_location field for existing classroom documents."""
+    ClassroomDocument = apps.get_model("bbb", "ClassroomDocument")
+    ClassroomDocument.objects.all().update(storage_location="AWS_S3")
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("bbb", "0024_classroomdocument_storage_location"),
+    ]
+
+    operations = [
+        migrations.RunPython(set_storage_location_to_aws, migrations.RunPython.noop),
+    ]

src/backend/marsha/deposit/migrations/0007_depositedfile_fill_storage_location.py

@@ -0,0 +1,19 @@
+# Generated by Django 5.0.9 on 2025-06-11 17:27
+
+from django.db import migrations
+
+
+def set_storage_location_to_aws(apps, schema_editor):
+    """Update the storage_location field for existing deposited files."""
+    DepositedFile = apps.get_model("deposit", "DepositedFile")
+    DepositedFile.objects.all().update(storage_location="AWS_S3")
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("deposit", "0006_depositedfile_storage_location"),
+    ]
+
+    operations = [
+        migrations.RunPython(set_storage_location_to_aws, migrations.RunPython.noop),
+    ]

src/backend/marsha/markdown/migrations/0008_markdownimage_fill_storage_location.py

@@ -0,0 +1,19 @@
+# Generated by Django 5.0.9 on 2025-06-11 17:37
+
+from django.db import migrations
+
+
+def set_storage_location_to_aws(apps, schema_editor):
+    """Update the storage_location field for existing markdown images."""
+    MarkdownImage = apps.get_model("markdown", "MarkdownImage")
+    MarkdownImage.objects.all().update(storage_location="AWS_S3")
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("markdown", "0007_markdownimage_storage_location"),
+    ]
+
+    operations = [
+        migrations.RunPython(set_storage_location_to_aws, migrations.RunPython.noop),
+    ]