fix: LANGUAGE_COOKIE_NAME is not set by default

Regression caused by https://github.com/edx/edx-platform/pull/28796

Details:

```
response.delete_cookie(
    settings.LANGUAGE_COOKIE_NAME,
    domain=settings.SHARED_COOKIE_DOMAIN
)
caused an Exception due to absence of LANGUAGE_COOKIE_NAME settings variable

> production.py

LANGUAGE_COOKIE_NAME = ENV_TOKENS.get('LANGUAGE_COOKIE', None) or ENV_TOKENS.get('LANGUAGE_COOKIE_NAME')
```

tutor/templates/apps/openedx/config/cms.env.json

@@ -35,6 +35,7 @@
   "EMAIL_USE_TLS": {{ "true" if SMTP_USE_TLS else "false" }},
   "HTTPS": "{{ "on" if ENABLE_HTTPS else "off" }}",
   "LANGUAGE_CODE": "{{ LANGUAGE_CODE }}",
+  "LANGUAGE_COOKIE_NAME": "{{ LANGUAGE_COOKIE_NAME }}",
   "SESSION_COOKIE_DOMAIN": ".{{ LMS_HOST|common_domain(CMS_HOST) }}",
   {{ patch("cms-env", separator=",\n", suffix=",")|indent(2) }}
   "CACHES": {

tutor/templates/apps/openedx/config/lms.env.json

@@ -45,6 +45,7 @@
   "ACE_ROUTING_KEY": "edx.lms.core.default",
   "HTTPS": "{{ "on" if ENABLE_HTTPS else "off" }}",
   "LANGUAGE_CODE": "{{ LANGUAGE_CODE }}",
+  "LANGUAGE_COOKIE_NAME": "{{ LANGUAGE_COOKIE_NAME }}",
   "SESSION_COOKIE_DOMAIN": ".{{ LMS_HOST|common_domain(CMS_HOST) }}",
   {{ patch("lms-env", separator=",\n", suffix=",")|indent(2) }}
   "CACHES": {

tutor/templates/config.yml

@@ -48,6 +48,7 @@ JWT_COMMON_SECRET_KEY: "{{ OPENEDX_SECRET_KEY }}"
 JWT_RSA_PRIVATE_KEY: "{{ 2048|rsa_private_key }}"
 K8S_NAMESPACE: "openedx"
 LANGUAGE_CODE: "en"
+LANGUAGE_COOKIE_NAME: "openedx-language-preference"
 MONGODB_HOST: "mongodb"
 MONGODB_DATABASE: "openedx"
 MONGODB_PORT: 27017