[fix] engine yahoo: replace fetch_traits by a list of languages

The Yahoo engine's fetch_traits function has been encountering an error in CI
jobs for several months [1], thus aborting the process for all other engines as
well.

The language selection dialog (which fetch_traits calls) requires an `EuConsent`
cookie. Strangely, the cookie is not needed for searching, which is why the
engine itself still works.

Since Yahoo won't be conquering any new marketplaces in the foreseeable future,
it should be sufficient to hard-implement the list of currently available
languages ​​(`yahoo_languages`).

[1] https://github.com/searxng/searxng/actions/runs/14720458830/job/41313149268

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/data/engine_traits.json

@@ -8576,46 +8576,6 @@
       "zh-classical": "zh-classical"
     }
   },
-  "yahoo": {
-    "all_locale": "any",
-    "custom": {},
-    "data_type": "traits_v1",
-    "languages": {
-      "ar": "ar",
-      "bg": "bg",
-      "cs": "cs",
-      "da": "da",
-      "de": "de",
-      "el": "el",
-      "en": "en",
-      "es": "es",
-      "et": "et",
-      "fi": "fi",
-      "fr": "fr",
-      "he": "he",
-      "hr": "hr",
-      "hu": "hu",
-      "it": "it",
-      "ja": "ja",
-      "ko": "ko",
-      "lt": "lt",
-      "lv": "lv",
-      "nl": "nl",
-      "no": "no",
-      "pl": "pl",
-      "pt": "pt",
-      "ro": "ro",
-      "ru": "ru",
-      "sk": "sk",
-      "sl": "sl",
-      "sv": "sv",
-      "th": "th",
-      "tr": "tr",
-      "zh_Hans": "zh_chs",
-      "zh_Hant": "zh_cht"
-    },
-    "regions": {}
-  },
   "z-library": {
     "all_locale": "",
     "custom": {