realm_export: Change tarball_size_bytes to PositiveBigIntegerField.

This commit updates `tarball_size_bytes` field from
`PositiveIntegerField` to `PositiveBigIntegerField` to support
larger values.

zerver/migrations/0624_alter_realmexport_tarball_size_bytes.py

@@ -0,0 +1,17 @@
+# Generated by Django 5.0.9 on 2024-11-14 05:12
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("zerver", "0623_merge_20241030_1835"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="realmexport",
+            name="tarball_size_bytes",
+            field=models.PositiveBigIntegerField(default=None, null=True),
+        ),
+    ]

zerver/models/realms.py

@@ -1368,5 +1368,5 @@ class RealmExport(models.Model):
     acting_user = models.ForeignKey("UserProfile", null=True, on_delete=models.SET_NULL)
     export_path = models.TextField(default=None, null=True)
     sha256sum_hex = models.CharField(default=None, null=True, max_length=64)
-    tarball_size_bytes = models.PositiveIntegerField(default=None, null=True)
+    tarball_size_bytes = models.PositiveBigIntegerField(default=None, null=True)
     stats = models.JSONField(default=None, null=True)