Confirm to Django's coding style

Follow Django's coding style conventions to keep the codebase
consistent, both with itself and with other projects.

References: https://docs.djangoproject.com/en/dev/internals/contributing/writing-code/coding-style/

Author: WhyNotHugo

django_afip/migrations/0017_no_null_string_fields.py

@@ -0,0 +1,92 @@
+# Generated by Django 5.2.9 on 2025-12-05 00:42
+from __future__ import annotations
+
+from django.db import migrations
+from django.db import models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("afip", "0016_clientvatcondition_receipt_client_vat_condition"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="pointofsales",
+            name="gross_income_condition",
+            field=models.CharField(
+                blank=True,
+                default="",
+                max_length=48,
+                verbose_name="gross income condition",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="pointofsales",
+            name="issuing_address",
+            field=models.TextField(
+                blank=True,
+                default="",
+                help_text="The address of the issuing entity as shown on receipts.",
+                verbose_name="issuing address",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="pointofsales",
+            name="issuing_email",
+            field=models.CharField(
+                blank=True,
+                default="",
+                help_text="The email of the issuing entity as shown on receipts.",
+                max_length=128,
+                verbose_name="issuing email",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="pointofsales",
+            name="issuing_name",
+            field=models.CharField(
+                blank=True,
+                default="",
+                help_text="The name of the issuing entity as shown on receipts.",
+                max_length=128,
+                verbose_name="issuing name",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="pointofsales",
+            name="sales_terms",
+            field=models.CharField(
+                blank=True,
+                default="",
+                help_text="The terms of the sale printed onto receipts by default "
+                "(eg: single payment, checking account, etc).",
+                max_length=48,
+                verbose_name="sales terms",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="pointofsales",
+            name="vat_condition",
+            field=models.CharField(
+                blank=True,
+                choices=[
+                    ("IVA Responsable Inscripto", "IVA Responsable Inscripto"),
+                    ("IVA Responsable No Inscripto", "IVA Responsable No Inscripto"),
+                    ("IVA Exento", "IVA Exento"),
+                    ("No Responsable IVA", "No Responsable IVA"),
+                    ("Responsable Monotributo", "Responsable Monotributo"),
+                ],
+                default="",
+                max_length=48,
+                verbose_name="vat condition",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="receiptpdf",
+            name="issuing_email",
+            field=models.CharField(
+                blank=True, default="", max_length=128, verbose_name="issuing email"
+            ),
+        ),
+    ]