[IMP] website: slug method also works with lazy values

Before this commit, the behavior is broken if using lazy values, the
condition using isinstance does not work. It's best to use the slug as
if given the correct value. Indeed, in odoo, we don't have any other
object having `id` as attributes in addition to `seo_name` or
`display_name` and not being a recordset and whose slug we want.
If there is an error, it is imperative that we provided a tuple (from
read).

Part-of: odoo/odoo#88276

addons/http_routing/models/ir_http.py

@@ -89,18 +89,18 @@ def slugify(s, max_length=0, path=False):
 
 
 def slug(value):
-    if isinstance(value, models.BaseModel):
+    try:
         if not value.id:
             raise ValueError("Cannot slug non-existent record %s" % value)
         # [(id, name)] = value.name_get()
         identifier, name = value.id, getattr(value, 'seo_name', False) or value.display_name
-    else:
+    except AttributeError:
         # assume name_search result tuple
         identifier, name = value
     slugname = slugify(name or '').strip().strip('-')
     if not slugname:
         return str(identifier)
-    return "%s-%d" % (slugname, identifier)
+    return f"{slugname}-{identifier}"
 
 
 # NOTE: as the pattern is used as it for the ModelConverter (ir_http.py), do not use any flags