fix: Preserve blank value for optional fields

modeltranslation/tests/tests.py

@@ -3871,3 +3871,19 @@ def test_managers_failure(self):
         ), "Permission is using MultilingualManager"
         user = User.objects.create(username="123", is_active=True)
         user.has_perm("test_perm")
+
+
+@pytest.mark.parametrize(
+    "field_name,expected",
+    [
+        ("title", False),
+        ("title_en", True),
+        ("title_de", True),
+        ("text", True),
+        ("text_en", True),
+        ("text_de", True),
+    ],
+)
+def test_field_blank_attrs(field_name: str, expected: bool):
+    field = models.TestModel._meta.get_field(field_name)
+    assert field.blank is expected