fix: custom validators for loans

loans/migrations/0005_alter_bookloan_loan_date.py

+# Generated by Django 5.0.7 on 2024-07-17 03:42
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('loans', '0004_alter_bookloan_book_alter_bookloan_member'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='bookloan',
+            name='loan_date',
+            field=models.DateTimeField(auto_now_add=True),
+        ),
+    ]

loans/migrations/0006_alter_bookloan_due_date.py

+# Generated by Django 5.0.7 on 2024-07-17 03:48
+
+import loans.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('loans', '0005_alter_bookloan_loan_date'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='bookloan',
+            name='due_date',
+            field=models.DateTimeField(validators=[loans.validators.validate_due_date]),
+        ),
+    ]

loans/migrations/0007_alter_bookloan_loan_date.py

+# Generated by Django 5.0.7 on 2024-07-17 04:05
+
+import loans.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('loans', '0006_alter_bookloan_due_date'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='bookloan',
+            name='loan_date',
+            field=models.DateTimeField(validators=[loans.validators.validate_loan_date]),
+        ),
+    ]