refactor!: clean up unused references to lms_web_url (#409)

Before edx-platform version 19ba691,
only `lms_web_url` was exposed from the course
blocks API. Now that the API also exposes
`legacy_web_url`, we can stop falling back
to `lms_web_url` when `legacy_web_url` is
absent.

TNL-7796

src/shared/data/__factories__/block.factory.js

@@ -46,17 +46,6 @@ Factory.define('block')
       return `${host}/xblock/${id}`;
     },
   )
-  .attr(
-    'lms_web_url',
-    ['legacy_web_url', 'host', 'courseId', 'id'],
-    (url, host, courseId, id) => {
-      if (url) {
-        return url;
-      }
-
-      return `${host}/courses/${courseId}/jump_to/${id}`;
-    },
-  )
   .attr(
     'legacy_web_url',
     ['legacy_web_url', 'host', 'courseId', 'id'],