[data] update searx.data - update_engine_traits.py (#4959)

Co-authored-by: searxng-bot <searxng-bot@users.noreply.github.com>

searx/data/engine_traits.json

@@ -7381,6 +7381,7 @@
       "ko": "korean",
       "ks": "kashmiri",
       "ku": "kurdish",
+      "kw": "cornish",
       "la": "latin",
       "lb": "luxembourgish",
       "ln": "lingala",