feat: remove Map.description

The field was not populated since years, and we already have the
info inside the JSONB `settings`.

umap/migrations/0021_remove_map_description.py

@@ -0,0 +1,16 @@
+# Generated by Django 5.0.4 on 2024-04-24 07:50
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("umap", "0020_alter_tilelayer_url_template"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="map",
+            name="description",
+        ),
+    ]

umap/models.py

@@ -155,7 +155,6 @@ class Map(NamedModel):
         (BLOCKED, _("Blocked")),
     )
     slug = models.SlugField(db_index=True)
-    description = models.TextField(blank=True, null=True, verbose_name=_("description"))
     center = models.PointField(geography=True, verbose_name=_("center"))
     zoom = models.IntegerField(default=7, verbose_name=_("zoom"))
     locate = models.BooleanField(
@@ -198,6 +197,13 @@ class Map(NamedModel):
     objects = models.Manager()
     public = PublicManager()
 
+    @property
+    def description(self):
+        try:
+            return self.settings["properties"]["description"]
+        except KeyError:
+            return ""
+
     @property
     def preview_settings(self):
         layers = self.datalayer_set.all()