fix: Ensure LMS_ROOT_URL is defined in i18n and assets settings modules (#1256)

When running the management commands related to translations
and static assets in `tutor/templates/build/openedx/Dockerfile`,
LMS_ROOT_URL needs to have a valid value, otherwise the build
will fail.

Tutor has relied on there being a valid value for LMS_ROOT_URL
present in `lms/envs/common.py` and `cms/envs/common.py`,
but upcoming changes to edx-platform (#37045) will create the
need to ensure LMS_ROOT_URL has a valid value.

Author: Taylor Payne

tutor/templates/build/openedx/settings/partials/assets.py

@@ -14,5 +14,8 @@
 DATABASES = {
     "default": {},
 }
+# Dummy value required for the static asset build steps to run,
+# but it has no impact on the output produced by those steps.
+LMS_ROOT_URL = "https://lms.local"
 
 {{ patch("openedx-common-assets-settings") }}

tutor/templates/build/openedx/settings/partials/i18n.py

@@ -9,6 +9,9 @@
 DATABASES = {
     "default": {},
 }
+# Dummy value required for the i18n build steps to run, but
+# it has no impact on the output produced by those steps.
+LMS_ROOT_URL = "https://lms.local"
 
 derive_settings(__name__)